Jason, you'll love Freedom of the Seas.
Dress is casual for breakfast and lunch anywhere on the ship. For dinner, there are two "formal" nights in the dining room where men will wear a suit or tux, and women wear cocktail dresses. The other nights in the dining room are informal, where the basic rule is anything but shorts. Some men wear jacket with open collar, some wear a nice shirt and slacks with no jacket. Women can wear dress, skirt or slacks.
For the dressy evenings, if you choose not to dress up, you can always go to the Windjammer, which has excellent food in a casual atmosphere.