DS was almost 9 when we went in January. We skipped Mission: Space because we were afraid it would make us sick (all of us, not just him). We skipped RnRC because we had heard the kids' heads get bounced around quite a bit. We skipped Splash Mtn. and Kali River Rapids because we didn't want to get wet (it wasn't nice enough weather to be wet!).
We rode ToT and DS HATED it! He really likes roller coasters, but ToT is different. He wanted to ride it but when it was over it turned out that he really didn't enjoy it AT ALL. He's not sure if he wants to try it again.
It really does depend on your children and what scares them. If they are tall enough they might want to ride everything! Have fun!