I'd echo what everyone else has said. Banana Beach is one of the best run, nicest and best value places on the island. And the staff is very friendly. Just wish there were more of this kind of place in Belize.
Belize First Magazine http://www.turq.com/belizefirst/
P.S. Try to get one of the corner seafront units on the second or third floors -- beautiful views and with balconies only a few feet from the sea.