(360) Active Online Arcade Games?

I am interested in getting an arcade game to play online if any are still Active or Fairly active. What Xbox 360 Arcade Games still have an active online community?? Not Street Fighter?

*I wish I bought Castlevania HD back when it came out, that looks like a lot of fun with multiplayer. *

Believe it or not, one of the earliest and best ever is still totally working! Battlefield 1943! It's is a absolute wonderful game. Online only but it always finds a game full of people the second I launch it!

I actually unlocked every achievement in it naturally. (I.e. not trying or even knowing what they are).

Also, I'm a WW II kinda guy, I still get my fix with the cool game mode that is Just two carriers. Us vs. Japan , I can't say enough good things about it.

Another one, But only the Demo is Battle Stations Midway, Its old, no one ever bought it but the demo is still super popular and people play it all the time! DL that one for free and try it.

I think I may have 1943 still way back on my download list. I'll go check, but more options would be nice.