Best XBOX Live titles?

I just got Live for my old xbox and am looking for some games that use the service well. I know Halo 2 has the web stats stuff, and Forza has car clubs and such. I think I remember a lot of people saying Phantom Dust had good multiplayer. Any other suggestions?

I always heard people liked crimson skies on live quite a bit.

oh and Splinter Cell Chaos Theory

If only Deathrow had been LIVE enabled… damn.

Project Gotham Racing 2 and Rallisport Challenge 2 for light racing, any of the 2K Sports titles for sports. Links 2004 for golf.

Wasn’t Deathrow announced as an Xbox Arcade title?

And another thumbs up for Phantom Dust. Man that game is just fantastic.