What content-type is suitable for files such as: .doc, .docx, .xls

Based on a configuration file of Laravel 3 , see the list of the most common ones used:

link

To make it easier to read in relation to the mimes requested in your question, here's the list:

  'docx'  => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
  'xlsx'  => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
  'word'  => 'application/msword',
  'xls'   => 'application/excel',
  'pdf'   => 'application/pdf'
  'psd'   => 'application/x-photoshop'

See the full list of some mimes used by default:

$mimes = array(
    'hqx'   => 'application/mac-binhex40',
    'cpt'   => 'application/mac-compactpro',
    'csv'   => array('text/x-comma-separated-values', 'text/comma-separated-values', 'application/octet-stream'),
    'bin'   => 'application/macbinary',
    'dms'   => 'application/octet-stream',
    'lha'   => 'application/octet-stream',
    'lzh'   => 'application/octet-stream',
    'exe'   => array('application/octet-stream', 'application/x-msdownload'),
    'class' => 'application/octet-stream',
    'psd'   => 'application/x-photoshop',
    'so'    => 'application/octet-stream',
    'sea'   => 'application/octet-stream',
    'dll'   => 'application/octet-stream',
    'oda'   => 'application/oda',
    'pdf'   => array('application/pdf', 'application/x-download'),
    'ai'    => 'application/postscript',
    'eps'   => 'application/postscript',
    'ps'    => 'application/postscript',
    'smi'   => 'application/smil',
    'smil'  => 'application/smil',
    'mif'   => 'application/vnd.mif',
    'xls'   => array('application/excel', 'application/vnd.ms-excel', 'application/msexcel'),
    'ppt'   => array('application/powerpoint', 'application/vnd.ms-powerpoint'),
    'wbxml' => 'application/wbxml',
    'wmlc'  => 'application/wmlc',
    'dcr'   => 'application/x-director',
    'dir'   => 'application/x-director',
    'dxr'   => 'application/x-director',
    'dvi'   => 'application/x-dvi',
    'gtar'  => 'application/x-gtar',
    'gz'    => 'application/x-gzip',
    'php'   => array('application/x-httpd-php', 'text/x-php'),
    'php4'  => 'application/x-httpd-php',
    'php3'  => 'application/x-httpd-php',
    'phtml' => 'application/x-httpd-php',
    'phps'  => 'application/x-httpd-php-source',
    'js'    => 'application/x-javascript',
    'swf'   => 'application/x-shockwave-flash',
    'sit'   => 'application/x-stuffit',
    'tar'   => 'application/x-tar',
    'tgz'   => array('application/x-tar', 'application/x-gzip-compressed'),
    'xhtml' => 'application/xhtml+xml',
    'xht'   => 'application/xhtml+xml',
    'zip'   => array('application/x-zip', 'application/zip', 'application/x-zip-compressed'),
    'mid'   => 'audio/midi',
    'midi'  => 'audio/midi',
    'mpga'  => 'audio/mpeg',
    'mp2'   => 'audio/mpeg',
    'mp3'   => array('audio/mpeg', 'audio/mpg', 'audio/mpeg3', 'audio/mp3'),
    'aif'   => 'audio/x-aiff',
    'aiff'  => 'audio/x-aiff',
    'aifc'  => 'audio/x-aiff',
    'ram'   => 'audio/x-pn-realaudio',
    'rm'    => 'audio/x-pn-realaudio',
    'rpm'   => 'audio/x-pn-realaudio-plugin',
    'ra'    => 'audio/x-realaudio',
    'rv'    => 'video/vnd.rn-realvideo',
    'wav'   => 'audio/x-wav',
    'bmp'   => 'image/bmp',
    'gif'   => 'image/gif',
    'jpeg'  => array('image/jpeg', 'image/pjpeg'),
    'jpg'   => array('image/jpeg', 'image/pjpeg'),
    'jpe'   => array('image/jpeg', 'image/pjpeg'),
    'png'   => 'image/png',
    'tiff'  => 'image/tiff',
    'tif'   => 'image/tiff',
    'css'   => 'text/css',
    'html'  => 'text/html',
    'htm'   => 'text/html',
    'shtml' => 'text/html',
    'txt'   => 'text/plain',
    'text'  => 'text/plain',
    'log'   => array('text/plain', 'text/x-log'),
    'rtx'   => 'text/richtext',
    'rtf'   => 'text/rtf',
    'xml'   => 'text/xml',
    'xsl'   => 'text/xml',
    'mpeg'  => 'video/mpeg',
    'mpg'   => 'video/mpeg',
    'mpe'   => 'video/mpeg',
    'qt'    => 'video/quicktime',
    'mov'   => 'video/quicktime',
    'avi'   => 'video/x-msvideo',
    'mp4'   => 'video/mp4',
    'wmv'   => 'video/x-ms-asf',
    'movie' => 'video/x-sgi-movie',
    'doc'   => 'application/msword',
    'docx'  => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
    'xlsx'  => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
    'word'  => array('application/msword', 'application/octet-stream'),
    'xl'    => 'application/excel',
    'eml'   => 'message/rfc822',
    'json'  => array('application/json', 'text/json'),
);

List with all correct MIME's for Office:

Reference: Office 2007 File Format MIME Types for HTTP Content Streaming

Complementing I leave a list of 220 content-type (obtained in the CakePHP 3 settings)

  

Link: Mime-types

[
    'html' => ['text/html', '*/*'],
    'json' => 'application/json',
    'xml' => ['application/xml', 'text/xml'],
    'rss' => 'application/rss+xml',
    'ai' => 'application/postscript',
    'bcpio' => 'application/x-bcpio',
    'bin' => 'application/octet-stream',
    'ccad' => 'application/clariscad',
    'cdf' => 'application/x-netcdf',
    'class' => 'application/octet-stream',
    'cpio' => 'application/x-cpio',
    'cpt' => 'application/mac-compactpro',
    'csh' => 'application/x-csh',
    'csv' => ['text/csv', 'application/vnd.ms-excel'],
    'dcr' => 'application/x-director',
    'dir' => 'application/x-director',
    'dms' => 'application/octet-stream',
    'doc' => 'application/msword',
    'docx' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
    'drw' => 'application/drafting',
    'dvi' => 'application/x-dvi',
    'dwg' => 'application/acad',
    'dxf' => 'application/dxf',
    'dxr' => 'application/x-director',
    'eot' => 'application/vnd.ms-fontobject',
    'eps' => 'application/postscript',
    'exe' => 'application/octet-stream',
    'ez' => 'application/andrew-inset',
    'flv' => 'video/x-flv',
    'gtar' => 'application/x-gtar',
    'gz' => 'application/x-gzip',
    'bz2' => 'application/x-bzip',
    '7z' => 'application/x-7z-compressed',
    'hdf' => 'application/x-hdf',
    'hqx' => 'application/mac-binhex40',
    'ico' => 'image/x-icon',
    'ips' => 'application/x-ipscript',
    'ipx' => 'application/x-ipix',
    'js' => 'application/javascript',
    'jsonapi' => 'application/vnd.api+json',
    'latex' => 'application/x-latex',
    'lha' => 'application/octet-stream',
    'lsp' => 'application/x-lisp',
    'lzh' => 'application/octet-stream',
    'man' => 'application/x-troff-man',
    'me' => 'application/x-troff-me',
    'mif' => 'application/vnd.mif',
    'ms' => 'application/x-troff-ms',
    'nc' => 'application/x-netcdf',
    'oda' => 'application/oda',
    'otf' => 'font/otf',
    'pdf' => 'application/pdf',
    'pgn' => 'application/x-chess-pgn',
    'pot' => 'application/vnd.ms-powerpoint',
    'pps' => 'application/vnd.ms-powerpoint',
    'ppt' => 'application/vnd.ms-powerpoint',
    'pptx' => 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
    'ppz' => 'application/vnd.ms-powerpoint',
    'pre' => 'application/x-freelance',
    'prt' => 'application/pro_eng',
    'ps' => 'application/postscript',
    'roff' => 'application/x-troff',
    'scm' => 'application/x-lotusscreencam',
    'set' => 'application/set',
    'sh' => 'application/x-sh',
    'shar' => 'application/x-shar',
    'sit' => 'application/x-stuffit',
    'skd' => 'application/x-koan',
    'skm' => 'application/x-koan',
    'skp' => 'application/x-koan',
    'skt' => 'application/x-koan',
    'smi' => 'application/smil',
    'smil' => 'application/smil',
    'sol' => 'application/solids',
    'spl' => 'application/x-futuresplash',
    'src' => 'application/x-wais-source',
    'step' => 'application/STEP',
    'stl' => 'application/SLA',
    'stp' => 'application/STEP',
    'sv4cpio' => 'application/x-sv4cpio',
    'sv4crc' => 'application/x-sv4crc',
    'svg' => 'image/svg+xml',
    'svgz' => 'image/svg+xml',
    'swf' => 'application/x-shockwave-flash',
    't' => 'application/x-troff',
    'tar' => 'application/x-tar',
    'tcl' => 'application/x-tcl',
    'tex' => 'application/x-tex',
    'texi' => 'application/x-texinfo',
    'texinfo' => 'application/x-texinfo',
    'tr' => 'application/x-troff',
    'tsp' => 'application/dsptype',
    'ttc' => 'font/ttf',
    'ttf' => 'font/ttf',
    'unv' => 'application/i-deas',
    'ustar' => 'application/x-ustar',
    'vcd' => 'application/x-cdlink',
    'vda' => 'application/vda',
    'xlc' => 'application/vnd.ms-excel',
    'xll' => 'application/vnd.ms-excel',
    'xlm' => 'application/vnd.ms-excel',
    'xls' => 'application/vnd.ms-excel',
    'xlsx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
    'xlw' => 'application/vnd.ms-excel',
    'zip' => 'application/zip',
    'aif' => 'audio/x-aiff',
    'aifc' => 'audio/x-aiff',
    'aiff' => 'audio/x-aiff',
    'au' => 'audio/basic',
    'kar' => 'audio/midi',
    'mid' => 'audio/midi',
    'midi' => 'audio/midi',
    'mp2' => 'audio/mpeg',
    'mp3' => 'audio/mpeg',
    'mpga' => 'audio/mpeg',
    'ogg' => 'audio/ogg',
    'oga' => 'audio/ogg',
    'spx' => 'audio/ogg',
    'ra' => 'audio/x-realaudio',
    'ram' => 'audio/x-pn-realaudio',
    'rm' => 'audio/x-pn-realaudio',
    'rpm' => 'audio/x-pn-realaudio-plugin',
    'snd' => 'audio/basic',
    'tsi' => 'audio/TSP-audio',
    'wav' => 'audio/x-wav',
    'aac' => 'audio/aac',
    'asc' => 'text/plain',
    'c' => 'text/plain',
    'cc' => 'text/plain',
    'css' => 'text/css',
    'etx' => 'text/x-setext',
    'f' => 'text/plain',
    'f90' => 'text/plain',
    'h' => 'text/plain',
    'hh' => 'text/plain',
    'htm' => ['text/html', '*/*'],
    'ics' => 'text/calendar',
    'm' => 'text/plain',
    'rtf' => 'text/rtf',
    'rtx' => 'text/richtext',
    'sgm' => 'text/sgml',
    'sgml' => 'text/sgml',
    'tsv' => 'text/tab-separated-values',
    'tpl' => 'text/template',
    'txt' => 'text/plain',
    'text' => 'text/plain',
    'avi' => 'video/x-msvideo',
    'fli' => 'video/x-fli',
    'mov' => 'video/quicktime',
    'movie' => 'video/x-sgi-movie',
    'mpe' => 'video/mpeg',
    'mpeg' => 'video/mpeg',
    'mpg' => 'video/mpeg',
    'qt' => 'video/quicktime',
    'viv' => 'video/vnd.vivo',
    'vivo' => 'video/vnd.vivo',
    'ogv' => 'video/ogg',
    'webm' => 'video/webm',
    'mp4' => 'video/mp4',
    'm4v' => 'video/mp4',
    'f4v' => 'video/mp4',
    'f4p' => 'video/mp4',
    'm4a' => 'audio/mp4',
    'f4a' => 'audio/mp4',
    'f4b' => 'audio/mp4',
    'gif' => 'image/gif',
    'ief' => 'image/ief',
    'jpg' => 'image/jpeg',
    'jpeg' => 'image/jpeg',
    'jpe' => 'image/jpeg',
    'pbm' => 'image/x-portable-bitmap',
    'pgm' => 'image/x-portable-graymap',
    'png' => 'image/png',
    'pnm' => 'image/x-portable-anymap',
    'ppm' => 'image/x-portable-pixmap',
    'ras' => 'image/cmu-raster',
    'rgb' => 'image/x-rgb',
    'tif' => 'image/tiff',
    'tiff' => 'image/tiff',
    'xbm' => 'image/x-xbitmap',
    'xpm' => 'image/x-xpixmap',
    'xwd' => 'image/x-xwindowdump',
    'ice' => 'x-conference/x-cooltalk',
    'iges' => 'model/iges',
    'igs' => 'model/iges',
    'mesh' => 'model/mesh',
    'msh' => 'model/mesh',
    'silo' => 'model/mesh',
    'vrml' => 'model/vrml',
    'wrl' => 'model/vrml',
    'mime' => 'www/mime',
    'pdb' => 'chemical/x-pdb',
    'xyz' => 'chemical/x-pdb',
    'javascript' => 'application/javascript',
    'form' => 'application/x-www-form-urlencoded',
    'file' => 'multipart/form-data',
    'xhtml' => ['application/xhtml+xml', 'application/xhtml', 'text/xhtml'],
    'xhtml-mobile' => 'application/vnd.wap.xhtml+xml',
    'atom' => 'application/atom+xml',
    'amf' => 'application/x-amf',
    'wap' => ['text/vnd.wap.wml', 'text/vnd.wap.wmlscript', 'image/vnd.wap.wbmp'],
    'wml' => 'text/vnd.wap.wml',
    'wmlscript' => 'text/vnd.wap.wmlscript',
    'wbmp' => 'image/vnd.wap.wbmp',
    'woff' => 'application/x-font-woff',
    'webp' => 'image/webp',
    'appcache' => 'text/cache-manifest',
    'manifest' => 'text/cache-manifest',
    'htc' => 'text/x-component',
    'rdf' => 'application/xml',
    'crx' => 'application/x-chrome-extension',
    'oex' => 'application/x-opera-extension',
    'xpi' => 'application/x-xpinstall',
    'safariextz' => 'application/octet-stream',
    'webapp' => 'application/x-web-app-manifest+json',
    'vcf' => 'text/x-vcard',
    'vtt' => 'text/vtt',
    'mkv' => 'video/x-matroska',
    'pkpass' => 'application/vnd.apple.pkpass',
    'ajax' => 'text/html'
]