Universal Hotels

Many people stay in one of the seven Universal hotels so they can get into the parks during special early hours and have easy access (sometimes a short walk or a free ferry ride) to the theme parks. All hotels offer early hours (you can enter one hour early) to Volcano Bay and two rides at one of the theme parks (Either Hippogriff and Forbidden Journey, or Minion and Gringotts). Staying at Loews Portofino, Hard Rock, and Loews Royal Pacific also gives guests express passes (skip the regular line) to most rides (but not Hagrid's or Pteranodon Flyers) at Universal Studios and Islands of Adventure theme parks!

Cabana Bay Beach Resort, one of the less expensive hotels, is perfect if you want to spend a lot of time at Volcano Bay waterpark- you can walk just a few feet to the waterpark from the hotel! It has great architecture with a 1950s theme, and bright rooms with floor to ceiling windows (that don't open). The pool, with reclining chairs on white sand, is fun at night after a day at the parks, though crowded. The lazy river is tropical and gorgeous, though watch your feet as they can get scraped up on the floor of the lazy river. There is a Starbucks, a cafeteria, and a bar with flamenco music at night. 
Endless Summer is the least expensive of the resorts, and is a bus ride away from the theme parks.
There are several hotels within walking distance of the Universal Studios and Islands of Adventure theme parks, and CityWalk, the dining area. Hard Rock Hotel is a very short walk from Universal Studios. It has tropical landscaping with bamboo groves galore. A slightly longer walk to Universal Studios, Loews Portofino Bay has colorful Italian architecture and opera singers performing in musica della notte at sunset in the harbor piazza. Their pool has peaceful trees around it. It is a lovely 0.8 mile walk around a lake to Universal Studios from this hotel. These two hotels are the most expensive of the seven. 
Closer to Islands of Adventure theme park, Loews Royal Pacific Resort is a short 0.4 mile walk past lush landscaping, and the third most expensive hotel. Just past it is Loews Sapphire Falls Resort, a 0.7 mile walk from Islands of Adventure theme park, and the least expensive of the four hotels served by water ferries. Aventura Hotel is just slightly further. It is one of the newest hotels, and more affordable. Its Bar 17 Bistro, a family-friendly 17th floor rooftop bar with incredible views is a great place to unwind after the parks! One can walk three minutes from Aventura Hotel to Sapphire Falls and catch the water taxi to the parks.
You can catch one of the free water taxis from Hard Rock Hotel, Loews Portofino Bay, Loews Royal Pacific Resort, and Loews Sapphire Falls Resort to the parks and CityWalk. Each hotel has its own dedicated ferry that runs every fifteen minutes starting 30 minutes before park opening. You don't have to be staying at the hotel to catch the ferry, except late at night.

Directions

Five of the hotels are walking distance from CityWalk and the two theme parks, with Aventura Hotel being the furthest (1 mile). You can also catch free ferries from four of the hotels to the theme parks, and from Aventura it's a three minute walk to Sapphire Falls where you can catch the ferry.
Cabana Bay Beach Resort is just steps from Volcano Bay waterpark, but a bus shuttle ride to the two theme parks. Endless Summer is a bus ride to the parks.
Parking at the hotels costs $25.

Click on map for interactive view