My wife and I've been to St. Croix, Cozumel, Kauai, Curacao, Playa, Cancun... and now San Pedro last October (2011). We're returning this coming April. It's the first place we've went back to. For the price, distance, and amenities for us (living in the Midwest US) it's perfect.
We're divers of course, but as the OP mentioned, we're not all about diving. We stayed at The Palms our first trip and dove next door with Romans. Loved them both. In April we're staying at Roman's. Actually, we found it to be cheaper than the Palms I think... or comparable and close, even considering a return discount to the Palms. But they're both great spots. Actually our ground floor at the Palms was the closest room to the ocean on that whole side of the island that we could see. We'll dive with Ramon's again but would also consider Chuck and Robbie's.
While traveling we're always looking for someplace that was nice and seemed to have a lot of things we like. Good diving, walking distance to shops, great local people, easy to get too. We found that on Ambergris. The diving is super easy as the reef is just 10 minutes away to many good spots and we could walk around town. I really liked the fact that the reef made the larger waves break out away's, meaning the short boat rides were pretty smooth even when it was windy. I don't do so well on rough seas and small boats. Plus, we literally got off the plane (twin prop) and walked down a block across the street to the Palms. Seriously, if you stay at the Palms or even Ramon's you don't need a cab (golf cart), it's literally a couple hundred yards at the most.
I liked the laid back pace of diving with Ramon's (Adolfo was great!). Now granted, that's all we dove with and from what I've seen, there's a lot of great operators there and everyone seems real nice. They would go out at 9, 11, and 2 pm. Show up if you want to dive, if not, no big deal. Plus the surface intervals are all done right there so we would even go back to our room and get a bite to eat. If we fell asleep and missed the next dive, no biggie. We lockered all our equipment at Roman's and so all we carried to dive each day was our room key and any snacks.
We went in October which was part of the slow season. A couple days it was just my wife and I diving. Other days it was a couple we'd gotten to know pretty well. Man... I'm getting so excited about going back again just writing this.
We purchased our flight straight to Belize city (Belize International) and then booked our own flight through
Tropic Air this time. They run every hour I believe (or something like that) from Belize City over to the air strip at San Pedro. You're hotel can make the reso for you also (which is what we did the first time) but they charged an extra fee.
It's funny you mentioned you've been wanting to go to San Pedro for 10 years. The night I met my wife 5 years ago I asked her, "If there's any place in the world you'd want to go, where would that be?" Her response, "Belize, because I've always wanted to learn to SCUBA dive and I hear it's great there." I said, "Me too!!" But then we've been a bunch of other places before going to San Pedro and are glad we did now because we have a lot to compare it to.
Although we're going back in April (a few months) we're also going to CocoView Roatan in September, another place on our bucket list.