Hmm... *checks RPM for ideas*
They have a general gaming forum (Gaming & Entertainment) with the subboard Emulation. The Emulation forum would be cool. Also, their Off the Wall forum (other discussion) has 4 subboards: Anime & Manga, Entertainment, Roleplay, Forum Games. They also have a challenge mode board, which would be cool to post challenges for various games (their's is MegaMan only) and have members beat them, or just post amazing things that you've done. The Fan Creations forum would be cool, where members post all their artwork and custom sprites and stuff. That's all that could really apply. Personally, I'd want either the Fan Creations-type board or a Challenge Mode-type one. Fan Creations more than the other.