It's important to clarify that you're likely asking about the chronological order of these games within the Sonic universe, not just the order in which they were released.
Here's the breakdown:
1. Sonic Adventure (1998)
* This game takes place first in the Sonic universe.
* Main Characters: Sonic, Tails, Knuckles, Amy, Big, Shadow (introduced for the first time)
2. Sonic Rush (2005)
* *Sonic Rush* takes place later, but the exact timeline is uncertain.
* Main Characters: Sonic, Tails, Blaze, Cream (introduced for the first time)
Important Notes:
* The *Sonic Rush* series contains several games, but the first game in the series is the one you are likely referring to.
* The Sonic timeline is quite complex and has been subject to some retcons and inconsistencies over the years.
I hope this helps!