Depends on what level of luxury you are looking for. I had a tremendous amount of fun in Roatan at Native Sons dive shop. It is in West End, and right in front of Chili's Hotel. Since I stayed at Chili's all my dives were $15 each, with night dives being $35 I believe. It wasn't super luxurious, but all I need is a decent bed to sleep in and don't care if I have to share a bathroom.

As for Utila, I recommend Utila Dive Center. They've got 3 or 4 boats still I think, and the UDC dock is the best place to grab a beer and watch the sun set. They also have BBQs every week (at least they still did 6 months ago), with lots of food, and fire spinners. If you want more of luxurious stay, try the Laguna Beach Resort. I can't say there is much difference in the staff, but there will be a big difference in the people you are diving with depending on where you go. Utila caters mostly to backpackers, but there are a few more upscale "resorts".

I've dived both Utila and Roatan. Roatan has slightly better dives, but is a little more expensive and a little less fun than Utila. At the end of the day, I think I prefer the "backpacker" situation of Utila a bit more even if it isn't always my scene. On Utila i would recomend UDC, Watersports, Laguna Beach resort, and Deep Blue. And Tranqulia is my favorite bar. Have fun!