I would definitely mention Cozumel! It's quite a bit different from Bonaire and Roatan. All drift diving and generally deeper. You don't have all the shallow stuff that's available in Bonaire. Some people find that a little more challenging, but I learned to dive in surge and current, so it's never bothered me. I've always liked drift diving. I think of it as "lazy man's diving." Drop in the water and let the current take you down the reef. The underwater scenery is absolutely spectacular. There are very few places in the Caribbean that come close.
There is definitely valet diving available. My personal preference is Aldora Divers, which also has a great place to stay, Villa Aldora. Some of the other operations frequently mentioned on this board are Blue XTSea, Living Underwater, Tres Pelicanos, and Scuba With Allison. Search the Cozumel forum and you will find more information that you can choke down. I will note here that Aldora has enough boats to group divers of similar experience and interests together.
My only reservation in recommending Cozumel is that I don't know what you are looking for in terms of "scenery." Cozumel is a low, flat island, so the top-side scenery is mostly a palapa, a palm tree, and a sunset. If that makes you happy, Cozumel is pretty scenic. If you are looking for something more dramatic in Cozumel, you need to be underwater. Even Bonaire has more topography than Cozumel.
If the scenic aspects work for you and you are not put off by drift diving, I would definitely recommend Cozumel.
Another destination in the same category is Little Cayman, which I would recommend over Grand Cayman or Cayman Brac. Again, a low, flat island where all the scenery is underwater, but it's spectacular scenery. The water is really calm and the diving is easy. It's very good for divers of all levels. Little Cayman Beach Resort is really nice and has a good valet-style dive operation, Reef Divers. It's really quiet. Dive, eat, sleep, lie in a hammock, and read. That's about it.