Chichen Itza (if you are into ruins) is great but as mentioned previously its about a 3hr boring drive each way, so count on being away from the resort for 7+ hours minimum
Private Tour Chichen ItzaBelow are some options for other private tours with shorter drive times provided by USA Transfers/Entertainment Plus
Private Tour Tulum Express This one is about 3 to 4hrs total
Private Tour Tulum & CobaThis one is about 4 to 5hrs total
Private Tour Tulum & Xel-haThis one is about 4 to 6hrs total - if you want the best combo of Mayan Ruins and a really fun water adventure - highly recommended
Cancun (the hotel zone - tourist area) is pretty much like any other big city, there are some great clubs there as well as Coco Bongo but they don't even get started until 10 pm.
Puerto Morelos - a small fishing village with some interesting local shops and decent restaurants is less than a half hour walk along the beach south of Pearl - definitely more cultural than you will find in Cancun - lol