Wow, where do I begin... there are so many differences:

1. Crush has one monster hit single (IML). Bounce has none.
2. Bounce rockers are heavier than Crush rockers.
3. Bounce used some of Creed's riffs, Crush doesn't.
4. Crush has one long, kickass guitar solo, Bounce has none.
5. Crush sells by the truckload, Bounce doesn't.
6. Crush is more commercial, Bounce is less commercial.
7. It took the band longer to write Crush than Bounce that's why I feel that the songs are generally better and catchier (although they are more pop than ever). Bounce could've been much better if they put more time going over the tracks in the studio. I think they might want to repeat the New Jersey trick for success, but it didn't work this time.
8. Bounce is 'more serious'. Crush is 'more fun'.
9. Bounce tend to be more overrated by die-hard fans, whereas Crush got a lot of flak from die-hard fans.

And those are only the beginning