Kingdom Hearts I is easily in my top ten games of all time.
It's all downhill after that as far as I'm concerned. KHII was so boring. The combat was sooooo button mashy. It was style over substance the second you turned it on. Mash X to watch Sora fly around the map destroying everything in his path, and then hit Triangle to do some QTE super move. It's not engaging at all. Whereas in the first one everything was more intricate. Your moves were more deliberate. Jump at just the right time, block at just the right time. Boss battles took far more concentration. You actually had to learn the bosses moveset, the right way to hit them and the right way to dodge them. It's a little cumbersome at first, yes, but far more satisfying in the end. The boss fight against Sephiroth in KHI... man, so intense.
And I shouldn't even need to say how absurd the story gets after KHI.
I've played every KH game (except for the mobile game), and I've never had as much fun with them as I had with KHI. Well, that's my KH rant. Thanks for your time.