Thank you all SO much for your tips! I've already begun scouring the internet for reviews and packages available for various cruises, and I think I'm armed with what I need to find a good one!
Btw, yes, we're both mid-twenties so definitely over 21, and while we don't NEED extreme luxury, we'll probably both be willing to spend the extra money to secure a nice room with a great view, and a cruiseline with excellent food.
Again, thanks for all the help! I'm sure this cruise is going to be fantastic!