It really depends on your taste.
Islands of Adventure has a lot of thrill rides (Hulk, Dueling Dragons, etc.) and water rides (JP River Adventure, Ripsaw Falls, Bilge-Rat Barges).
Universal Studios has a lot of movie themed stuff, and less thrill rides (besides of course HRRR, which should be open soon).
Perhaps go to the website and look at the rides at each park, see what is most suited to you.