You have just opened the Pandora's Box of cruise questions. This is an age old arguement that has no real true answer.
Perhaps better addressed if you tell us a few things. 1) where are you going? (what ports and the hours).2) What do you like to do? (beach, snorkel, shop, historic sightseeing, other activities etc). 3) what would you consider your activity level?
4) how adventurous are you?
It would probably be easier to guide you to specific things rather than try to answer your question with a big generic answer.