carnival is where you want to be---they have more of the atmosphere you are looking for---the other all inclusive lines is most likley not what you are looking for---they are more consitant of higher more well traveled clients and not looking for party---no nightlife and no party by the pool...

You will pay for the buckets of beer on Carnival and the bar tab will run up quickly as others have mentioned, but 4 or 5 day on them can be as cheap as 600 where as silversea, seabourne will run you 5,000 or so.