you can also book through hotelkingdom.com, they often have decent discounts. If you are lucky, you might be able to get an entertainment discount (they aren't always available) if you have an entertainment book (can buy at entertainment.com). You have to call the hotel directly to find out (1-800-beastar). If a company you work for participates, you can get a fan club discount (enter FAN). If you buy an annual pass, you can get a discount. Just enter APH in the discount code box on the reservation page at universalorlando.com or loewshotels.com
It seems that the APH or Entertainment discounts are usually the best. HTH