Whew, finished this thread! I'm surprised by seeing Sci-Fi mentioned so frequently, makes me nervous for my next trip... I haven't been in 5 years and it has always been a favorite for good-enough food and fun theming. I've never had an outstanding meal there, but never had a bad one, either. Hopefully it hasn't slipped in that time.
To be honest, I've never had a truly BAD experience with food at Disney. Gumbo at Boatwright's didn't agree with me years ago, but that's about the worst I can think of to complain about. However, I agree with some comments that there are restaurants that are worth skipping over for, if not being bad, being blah. I gave up on CRT a decade ago, and it sounds like I haven't missed much! Food was always aggressively mediocre, and the experience never made up for it in my opinion. Tony's was a favorite from childhood, my last trip will probably be my last for a few years; the food just isn't up to par.
The only truly *disappointing* meal that still stands out to me is Coral Reef. I was really looking forward to the experience, and everything fell flat, from the food to the service, and even the atmosphere. Sure, the fish tank is cool, but that's about all I thought it had going for it. That being said, nobody was actively rude to us, and the food was edible even though I didn't particularly enjoy it. I live in CA's wine country so maybe I am spoiled by all of our good dining options, and I really don't expect my Disney dining experiences to be the best I have all year, but I want to at least enjoy my meal, whether it's because of the food, the service, or the theming. If all three fall flat... I'll give the restaurant a pass on my next trip and try something else out next go around.