We only got the one day pass but I tell you its better to get a two day pass because Universal Studio would take the whole day to explore, that is if you want to ride every rides and check out every attractions. That's why we didn't try some of the rides BUT we surely tried one of the best rides they have. We started in Hollywood where there are street performances and the musical Monster Rock (first musical and its a great show), then New York where the The Rockafellas (former Streetboys) performed, Lights, Camera, Action hosted by Steven Spielberg, Sesame Street Spaghetti Chase (adults may not really enjoy it but surely kids and kids at heart would love the ride), then Sci-Fi City where they have the Transformers the ride: The Ultimate 3D battle (the best ride ever!) then Ancient Egypt where we tried the indoor roller coaster Revenge of the Mummy (another first for us and am probably not gonna do it again), then the Lost World (we didn't tried any of the rides either you need another set of clothes or a rain coat for the water rides which I really want or the line is too long), Far Far Away where we watched Donkey's live show (we had a good laugh with Donkey and Raul) and lastly Madagascar where we tried the Madagascar: A crate adventure. There are a lot of attractions that we missed but we are just happy that we were able to visit and had fun and definitely we are going back.
Get a two day pass. One day for the S.E.A Aqurium and another day for Universal Studio. It will take half a day for your sight seeing and S.E.A Aquarium and if you wanna enjoy Universal Studio then you need a whole day for that.
Transformers the ride is the longest and the most tiring line ever! people were complaining and getting tired (well I saw some rides that have long lines but I think no one can beat this line) but its all worth it. Better make it first on your list or line up early, unless you will purchase an express card which is quiet expensive but they prioritize people with an express card.
Lost world rides are awesome. Canopy ride is popular so better line up first, they have Rapid adventures which I bet is cool but you either need a set of clothes or a raincoat which we didn't have so we never tried any rides in Lost world.