My wife and I will be in Key West in early May and are trying to get ideas for some good restaurant choices. My wife doesn't like seafood, so we'd like suggestions of good restaurants that are nice, but not overly expensive. Just good food and a fun atmosphere. We're a retired couple and not necessarily looking for a wild party atmosphere. Thanks

7 Fish - casual but very good. They have other things beside fish.
Banana Cafe - french,
Alice's at La te Da - funky but good
Mangoe's - Good pizzas and sandwiches
Pepes - very good for any meal

I'll add to that list El Siboney, which is a very inexpensive Cuban restaurant.
Key West has a wonderful little booklet called "The Menu" that's available all over town and includes menus from lots -but not all - of the restaurants in town. Pick one up when you get to Key West and it'll help you select a restaurant that appeals to you. It's also available online at keywest.com/themenu/menus.htm

Thanks for the advice!

Oh yes El Siboney is THE BEST!

I am not a seafood eater, but my husband is. So, a lot of compromising goes into our restaurant choices.

I love Bagatelle, Margaritaville (I know, I know - but it is a first night in Key West tradition for us to have cheeseburgers, black bean soup, etc.), Banana Cafe for breakfast, La Tratorria, A & B Lobster House, Pepe's, Alonzo's Oyster Bar, Meteor Grill - I am actually forgetting some of the other places we like. Uh, oh.
One more piece of advice that the sage Grglnswsh gives - never eat at places that hand out flyers/coupons on the street. That one I always take with me!!

Enjoy your trip!!