Have you tried the Groove Cruise? I went last year and it was a blast. It is more of a party cruise with the best DJ's around and private beach, pool and all night parties. Plus there are a ton of beautiful Men & women onboard. The groups age range is approx 21-40.
I found a coupon for $50pp off the cruise (Code: MEETUP)
they also will find you a same sex room mate if travelling alone and wanting to cut costs.
All the info is at www.theGroovecruise.com
Tons of videos and pictures on their web site from last year
Definitly a fun and exciting cruise expereince.
Hope this helps