Cancun, Mexico
If you like to be on top of things, this is one place you have to visit. The top of the pyramid at Chichen Itza. You can see forever. Someday they are going to have to close this off to visitors, so get there soon and take your camera.
This is one "AWESOME" hotel - The Ceasar Park Hotel. Top notch.
I've found that the best time to visit Cancun is in the fall - just after hurricane season. There are very few people there then and they offer fantastic package deals. Go with an "all-inclusive" deal and bring a couple hundred $ spending money. Even though the beach is my favorite place to spend time, you must visit the ruins. There are several to choose from but Chichen Itza is the most impressive.