My Advice:
Get the Express Pass. Since we stayed at a hotel, we had the Express Pass built into the price of our visit. However, if you are not staying at one of the on-property hotels... get the Express Pass anyway! It cuts all the lines into easy, less than 10 minute pieces! (Some rides, like Harry Potter, don't have Express lines.)
Don't even think about comparing the Universal Express Pass to the Disney FastPass. The FastPasses have a seperate line... but they tell you when to go to the ride and the times aren't distributed evenly. (My sister and great aunt got a FastPass... but there were so many 4:30 FastPasses that the lines were all of equal length!)
Top 3 Rides:
1) Harry Potter and the Forbidden Journey. The latest ride from Universal... with no disappointments! Great simulation... and it's a plus if you've seen all of the movies and read all of the books.
2) The Simpsons Ride. Finally! A ride that combines excellent simulation techs with good ol' Simpson humor!
3) The Amazing Adventures of Spiderman. More simulation... with a 3-D twist!
More to come...