Sonic 3D Blast came before Sonic Adventure.
Sonic heros.
Sonic Adventure 2 By The SuperAmr!!!!!!!!!!!!!
Sonic Adventure
Sonic R. Made in 1997 for the Sega Saturn and PC. Also in Sonic Gems Collection for the GameCube and PlayStation2.
Sonic adventure battle 2
You can click download game trial after clicking sonic adventure at the game marketplace.
sonic unleashed was intended to be sonic adventure 3 before the name changed.
Sonic adventure 1 and 2
Sonic Adventure Battle (DC/GC) and Sonic Adventure Battle 2 (DC/GC)
well, sonic unleashed was originally gonna be called sonic adventure 3, then sonic world adventure which was gonna be the 3rd sonic adventure game, but then they had to come out with werehog and didnt make it the third sonic adventure. but they might be making a new one late 2009 or antime 2010
Whilst debatable due to Cream's cameo in Sonic Adventure DX, I would say no, both the games are set after Sonic Adventure. Whilst Cream does indeed appear in Sonic Adventure's re-release, it was only for a short moment, and she has no contact with Sonic whatsoever. On top of that, when they meet in Sonic Advance 2, it is shown that despite her knowing of him, Sonic himself has never seen her before. Because of this, I would assume that Sonic Advance 1 and 2 take place after Sonic Adventure.
It is already out. The sequel to that game is called Sonic Adventure 2: Battle. Dx is a re release of sonic adventure, and they also re released sonic adventure 2.