What is your skill level? Do you want flat water, ocean, lagoon or waves? What is your hotel budget for a week? When are you going? Wild party all night or laid back and romantic? Stay in one spot or travel around (car rental). I'll get you the info.
Tom
http://www.cozumeltom.com

Just got back from Cozumel. Awesome. Kited every day for a week straight with Adrian from CozumelKiteboarding.com. Steady, consistant winds and plenty of different terrains (smooth in the lagoon, waves offshore, flat water, etc.) Highly recommend that place.