Yes, I can not stress this enough. Getting there early gets you on many rides that you will have to wait for later.
We've gone to IOA early, and gotten rides on Spiderman, Dr. Doom, JRPA, and Hulk even before the crowds. Another time we did the opposite side of the parks, and was the first riders on Cat in the Hat (we actually saw mistakes!), and One Fish Two Fish.
At USF, many re rides in MIB. And a not as full T2, walk on on ET, first show at Animal Planet.. you name it.
I think one day we did 10 rides at MIB...