suggestions for cruise of family w/ kids over 21

So for my college graduation present my parents want to take my brother who is 26 and myself who will be 21 on a cruise. I was hoping for some suggestions on cruise lines that have young adults on the ship but also are accommodating and fun for parents in their mid to late 50's?

Any suggestions are much appreciated.

Welcome to Cruise Critic and congrats on your upcoming graduation.

The lines that seem to most appeal to young adults would be Carnival, Royal Cribbean and Norwegian.

I have to agree...the above mentioned lines will have more young adults (neither of you are "kids" anymore!) than the slightly more "upscale" Hal, Celebrity and Princess.

I'm in my twenties, and prefer HAL and Royal Caribbean over Celebrity. I found Celebrity to be a bit more upscale. In some things this is great (like the food), but in entertainment I found it lacked what I was looking for.

I've tried Norwegian too, but still prefer Royal Caribbean for the entertainment and HAL for everything else.

NCl Epic