Anticitizen One said:
I haven't played a sonic game since Sonic Adventure 2 on gamecube. Which newer ones should I check out?
All of the handhelds.
Sonic Advance 1-3 and Sonic Rush and Sonic Rush Adventure.
Other than that, Unleashed (360 version) is pretty much the only thing worth playing.
Heroes is a buggy mess (great idea, terrible gameplay, cheap deaths galore, etc) with terrible voiceovers, Shadow the Hedgehog shouldn't exist, and Secret Rings goes anywhere from decent to terrible and frequently switches back and forth about how annoying it wants to be.
I haven't played Sonic and the Black Knight, and according to my brother who has the Wii version of Unleashed, it's much worse than the 360 version.
As for Sonic Riders, I have the Gamecube version, and surprisingly, I thoroughly enjoy it. It totally destroys your control sticks (requires you to spin them as fast as you can in every track) and doesn't tell you how to play, but once you figure out what to do, the game is actually pretty fun.
I haven't played Riders: Zero Gravity though, so I don't know about that one.
Am I missing anything?