After seeing many requests or releases of characters from a wide variety of games, does anyone know of other sites/forums that hosts mods? What are the more popular games for modding?

Just don't link any valve/elder scrolls/fallout games. Mods for those are easier to find then bread.

For some reason I picture Leon in DMC3 >_>

Hell's Atelier for DMC modding

As for others, I do not know.