The only character meal we did without kids was LTT. It was early in the character meal thing, so the characters interacted with us quite a bit. At most of the others, we've felt a little bit let down with the amount of character interaction. They will spend twice as long at your table if you have an autograph book to sign, as if you are just taking pictures. That just doesn't seem fair to me.
Also, they are fun, but don't expect a relaxing meal. I wouldn't doone every day, because they just aren't quiet and relaxing.
As far as food goes, the better ones include CP, CM (breakfast and dinner), don't know personally about the new one at MGM but I hear it is good, 1900 Parke Fare (quite noisy though). Garden Grove had pretty good food and great character interaction. Aslo, this one is not as noisy as many of the others. We did breakfast, but the dinner looked good too.
The lesser food ones are CRT (do it once for the atmosphere, but don't expect stellar food, book on the first day you can, call at 7am) and LTT (unless you really like Thanksgiving type food. It wasn't bad, just not exciting food.) My sister did the princess one at Epcot, and didn't like the food very much, though the princess part was nice.
We've never done 'Ohana, Donald's B, Garden Grill had a different menu the last time we did it; the setting is actually kind of cool, but the food has gotten okay reviews. Plus we really like the new Seasons place below for lunch. Cape May looks good, but also fills up.
Then there are a few places that are not character meals, but fun without the characters: Prime Time Cafe, House of Blues, and Whispering Canyon. WC even has some pretty good food. PTC has great fried chicken, but otherwise expect traditional American food. the Mexican place in Epcot was a cool setting. The food was a little pricey, but I liked mine.
Some of the more adult places we've enjoyed are Boma (not for everyone though), Marrakesh, Big River Grille, Flying Fish, California Grill (sat in bar area, no ressies, appetizers in a cool setting, great sushi), Kimono's (a bit pricey, but good for a sushi fix), Yacht ClubGalley (great steak sandwich)