My wife and I have gone there twice in Orlando. We're thinking of going there again this year but trying to decide if we will do Disney World (exclusively) instead. I highly recommend Universal Studios and both theme parks. CityWalk is a lot of fun also. We enjoyed the heck out of the original Harry Potter attraction. Like Stash, we haven't experienced the newer Potter attraction but I'm sure it rocks too. If you're thinking of staying at the resort, I recommend the Hard Rock Hotel. It's located nearest to both parks and a short walk away. Plus the service, rooms and amenities are fantastic. The Hard Rock is one of the main reasons why I want to go back to Universal.
EDIT: Get Express Passes for the parks! They cost more but well worth the money for avoiding long depressing lines.