GoodFileShare features a wide range of classic DOS games, previously unreleased titles, and even some “modern” DOS titles. The entire site is “dedicated to preserving classic games for defunct PC operating systems” such as DOS, CP/M-86, OS/2, Win16, and Win9x, as well as making them easier to play on modern systems.
GoodFileShare's Homepage here
Email: goodfileshare@gmail.com
You can search for games using genre and operating system, as well as the company name, legal status, year released, and interestingly, video mode. Furthermore, testament to RGB Classic Games mission, you can play a significant number of titles on a site-hosted emulator, including Keen Dreams, Hexen, and one of my all-time favorites, Transport Tycoon.