Best cruise line for family/teenagers?

Travel Info
warm waters - grandmother-daughters & 2 teenagers

Travel Tips

I would say Royal Caribbean, they have a lot of activities tailored to both age ranges. You might also look at Disney, but they don't have as many options for destinations.

Others
there are quite a few to choose from. cannberra, princess cruises. for the more informal i would reccomend thomson cruises.
Try Norwegian Cruise Line (NCL). They have great food as well as activities both on board and land excursions. They aren't too expensive, and in my experience- offered a more enjoyable experience than Royal Caribbean.