Depending on your age here's my suggestions:
50+ Holland
30-50 - Royal Caribbean, Princess, Celebrity
18-30 - Carnival
If you are traveling with kids - Disney
Carnival is for young partyers who care more about drinking, socializing, hooking up with other younger travelers etc. Food is below average and so are the amenities.
Holland is fantastic all the way around, the only down fall is the age of the travelers. It's geared towards senior citizens.
Royal, Celebrity, Princess are all above average cruise lines.
Hope I helped, happy traveling.