After reading all these most loved and most hated all I can think is there really is something for everyone in the Orlando parks. Someone's most loved is someone else's most loathed.
I can't pick a favorite. Or a most reviled. It all depends on the audience I'm doing it with or what I characterize as good or bad about an attraction.
I keep seeing Tiki Room mentioned as a hated attraction, but I would disagree. Is it my favorite, no, but I admire it every time I do it. It is THE original AA attraction, designed by WALT himself. You have to admire the history there (even if this isn't the original) and the simple charm of it all and think of how amazing it was when it first opened 50+ years ago at DL.
I get the hate of the shows like Nemo and BatB, but if you're watching with a young niece, they can be the best thing you do all day.
It's like when people rank roller coasters. How do you say that a coaster like Millennium Force is better than Big Thunder Mountain Railway? Both are excellent for completely different reasons and audiences. Almost every attraction (with relatively few exceptions) has some fan base/audience that even if it doesn't appeal to you, someone not only likes it, but it may be their favorite thing they do or see on their trip to Orlando.