I've been to Cedar Point, Universal, Silver Dollar City and a couple of Six Flags- that's off the top of my head. I'd have to look at the list again, but at least those. I'm sure I went to more in my younger days I've blocked out.

Other than trying Universal last year, it's been a very long time since I went to any. I don't think they've changed in any way that would change my mind about them though.
Theme parks, amusement parks- I consider them to all be pretty much the same, but that's just terminology and really beside the point. I don't like them because I don't like parks where the main focus seems to be on how extreme a ride can they make- where they focus on the rides, rather than the experience. I understand completely some folks love them, and that's fine. If one is really into riding a coaster that peels your skin off your face, I can see where WDW might fall short.