I found a major error in the Cheats page, and since there's only one guy working on this site, I had to close the Cheats page. I don't have enough time to keep adding the cheats, because there is a lot of DC games coming out. So, here is a good cheats websites:

Game Sages - A very very good cheats page, has every single Dreamcast game cheat.

Cheat Guide - An okay cheats web page, has cheats for most of the Dreamcast games.

Cheat Heaven - Another okay cheats page, doesn't really have a lot of cheats, but still a very good site.

Super Cheats - A very good cheats page, has some cheats for Saturn also.