T-REX! We thought the food was tremendously better and the atmosphere is just awesome with life-like T-Rexes, fish tanks, meteor storms, "ice" cave that lights up in changing colors, and the giant moving octopus over the bar. It is a LOUD place though, if that's a concern.
One hint about making reservations at T-Rex (and maybe Rainforest too, I'm not sure) - they don't put all their open reservation slots on the Disney website. It almost always shows no reservation times available at peak lunch and dinner times, but if you call them, they have availability. I read somewhere it is an independent restaurant operating on Disney property, and that's just how they choose to do it.