How about MTA (Multi Theft Auto), GTA multiplayer style?
I used to play it a bit (SA), but because of the servers being full of complete asses and admins using their powers to their own advantage (and actually mine too) I stopped - and it wasn't on one it happened, it happened on all...
However, I'd really like to see a BlackIntel server there, as it, as I recall, was quite a popular game. So if we can attract the right kind of people there, we should also be able to become more popular.
I don't know much about how it's run, etc. but I'll begin to look into it if others support it.