I wanted to personally recommend the Howler Money Lodge, about 30 minutes outside of Belize City. This was a fantastic place to stay in the jungle and the owners, Ed and Melissa, were fantastic hosts and took plenty of time away from their day to show us around. Melissa cooked the best breakfast I have had in years!
My wife and I did a night river tour insearch of iguanas and crocodiles (sp?) and saw 8-10, some as big as 8-10 feet long. Then next day we went with Ed to the zoo and then on the cave tubing trip which was the most amazing thing I have done in my whole life.
The Howler Monkey Lodge is very inexpensive, and comfortable even though there is no AC. It wasn't even needed and we slept great! I can't wait to go back!