Went last year for a wedding! Stayed in El Dorado Royal on the main road between Cancun and Playa de Carmen.
Xel-Ha was fuckin wicked i LOVED it!!!!

Completely open theme water park.. And the fish

Some big fuckers aswell!
Go deep sea fishing, it's cheap and good fun! We caught some barricudas and a snapper fish!
Here's a few pictures of fishing and Xel-Ha...
Hotel
Fishing..
Xel-Ha
You'll enjoy yourself