If you want a resort, I suggest you stay at the Casa Marina. They have the nicest grounds and facilities, but are not close to the action on Duval Street.

If you want close to Duval Street, but still want a nice full-service hotel; I suggest the Pier House.

You won't go wrong with either property. If you want small and cute, there are some good inns/small hotels around town. These include Key Lime Inn, Island City House, Marquessa Hotel, L'habitation, and the Cocoplum Inn.