Destinations in Cancun and Riviera Maya are amazing and Cancun Transportation can take you anywhere at any time!
Cancun Hotel Zone is pretty close to the Cancun Airport but private transportation is a must since there is no public transportation from the Airport.
Playa del Carmen is about 55 minutes from the Cancun Airport depending where exactly you are staying. It's very cosmopolitan and the main path to get to Cozumel.
Tulum is about 1:30 hours from the Cancun Airport and is the hip destination of the area. Private Transportation to Tulum is always more comfortable and fast.