Cancun

white sand, warm blue sea.. loved it

Cancun is good if all you want is beach and sun, but not if you want anything to do with Mexico. Cancun is basically a giant frat party, completely devoid of culture or anything interesting/unique/Mexican, that happens to be on a pretty beach. I found it downright depressing.

went there during springbreak. party all day and all night. if that’s what you are looking for, definately go.

Want to enjoy the sun, beach, scuba diving, snorkeling

Mini America in Mexico, so not much of different culture stuff there. But the ocean is beautiful. You can have a relaxed holiday at one of the hotels on the strip, almost every hotel faces the ocean.
Super expensive!
Oh it has great night life. I love their bars and the dancing.