As others have stated, Paradise Villas offers the best of both worlds - a very private and quiet setting right on the beach, but just steps away from shops, restaurants, grocery stores, etc. available in San Pedro.
We had considered booking a place further north on the Caye (where it would have been more private and secluded), but now that we've been here for a week, we're very happy that we stayed where we did. Some of the other resorts are several miles from town, and although they advertise that it's only a few minute drive by golfcart to get into town, they generally don't tell you that it's a very bumpy dirt road. It's kind of a fun ride once or twice, but not something you want to be doing every day. And trust me, there is so much good, and cheap, local food options in San Pedro, you don't want to be stuck eating at the same resort restaurant 3 meals a day for a week!