Hey, if you wanna party then I'll go for Cancun and the main reason for that is cause everyone goes to Cancun so you'll have a lot of people with the same mood as you. Also cause there a lot of cool bars and clubs (ex."Alebrije")
On the other hand it can get a bit expensive so you might want to consider "Playa del Carmen" which is really close to Cancun, a bit quieter and much cheaper and who has the famous "5th avenue" where all the nice clubs and bars are (ex.Blue parrot). Also you can go visit some archeological sites since you're on the zone and Tulum is a nice place to visit :) about 10 years agoAnswered by Mafer Kendel via Travellr.com
Miami is also a great party city during the March/April spring break time, but be sure you stay in South Beach - it's where many of the clubs, hotels, hostels, and party beaches are, and most everything is within walking distance there. It's an old favorite of mine.
Cabo is supposed to be nice - I've never been, but I've heard a lot of buzz about it. Other off-the-beaten-path but still hot places are:
South Padre Island, Texas
Google around and see what buzz you can find (you could also check facebook) about anywhere along the Gulf Coast and the Mexican Baja Peninsula. There tend to be lots of great spots! about 10 years ago