Salamander2 posted the following idea in this topic over at DCEmulation.com:

also, ive mentioned before the RETRO REMAKES page. they are almost all SDL and code free. take a look on the great number of games that could run on the dreamcast.)
Seems he means this site:
http://www.ovine.net/Retro-Remakes.php

Another nice site with loads of games & links I've found googling for "retro remakes":
http://www.remakes.org/