DOS Gamer - Collection of freeware, shareware, and trialware. - http://www.dosgamer.com/
Classic DOS Games - Reviews and downloads of classic games. Attempts to archive complete version history of each game, with source code. - http://www.classicdosgames.com
Dos Games Download - Reviews and downloads of DOS games, organized by category. - http://www.dosgamesdownload.com
Wally4000 - Focuses on DOS games, and is the home of the DOS Games Windows XP Compatibility List. Also includes some Mac and Windows games. - http://www.dosgames.com/~wally4000/
Old School DOS Games - Games available for download. Also offers information on DOS emulators. - http://www.oldschooldos.com/
DOS Games Online - Downloads and reviews of over 400 freeware and shareware DOS games. - http://www.dosgamesonline.com
DOS Games Archive - Large collection of shareware and freeware DOS games, all available for download. The games can be organized alphabetically, by genre and by version. Also includes an online DOS game shop. - http://www.dosgamesarchive.com/
DOS Games - Over 400 shareware and freeware games organized into fifteen categories. Also available are associated utilities and a message board to find old games, get games working or discuss DOS games. - http://www.dosgames.com/