The place in Belize that I really enjoy staying at is called Chaa Creek Lodge. They used to run on gas, but as of my last visit there in February of 2000, they had installed electricity in the rooms and the main lodge. Also, the food that they serve here is wonderful, and even though this is a resort, I don't really consider it to be resorty. There is a Blue Morpho butterfly farm very near by, that is pretty cool. This place is in the rainforest near the Guatemala boarder.
If you wanted to stay on the islands, I recommend Jaguar Reef. This is very off the beaten path and I would consider it to be very romantic. The food here was excellent as well.
Belize City has some nice restaurants and lovely B&B's, but I recommend staying away from the main hotel in Belize City. (I can't remember the name right now, but it the only non-mom&pop type place.) The views from the rooms are lovely but the B&B's in Belize City have so much more to offer.
I have more names and phone numbers at home. If you are interested in more information, let me know and I will bring it in to the office with me.
I've been to every country in Central America except Panama, and would highly recommend having a visit in Belize.
Cat in Chicago