For the record:
Xenogears: A tremendous achievement of storytelling that (much like Eva) ran out of funding and time, resulting in half of an awesome game and half of something... else...
Kingdom Hearts: I loved the first game because it was you and Donald Duck on a magical adventure. KH2 had some great gameplay and awesome set-piece moments, but it felt like the series got away from the core roots that made it so whimsical and fun. As of late, the series has been milked and processed to the point of complete garbage, and I'm not even sure if a third core entry could right the ship.
TWEWY: That shit is awful. Seriously, though, the gameplay just baffled me and I had no interest in the main character.
Xenogears: I had no problem with the second disc, as a whole the game was great from start to finish(though I do agree the sewer portion was a little lame), the only thing that pissed me off was that the game ended as Episode 5. While Xenosaga did come out and was overall a good somewhat successor(it had a lame ep 2), it still didn't completely encompass the greatness of the first game. So unfortunately due to all the licensing and sales, I have to reluctantly refer to Xenogears Perfect Works, have you heard about/read that?
Kingdom Hearts: I think maybe I just like Nomura's style, but I found KH 1/2 to be highly enjoyable. Birth by sleep as well. Coded, 358/2, and Chain of Memories were all pretty bad though. The story did go over the top, but I still enjoyed it. I think when they finally do get to number III, it might end up being alright. I think they just need to make III then end it with possibly wrapping up every single mystery they have, even if they have to retcon, but there should be a definitive ending. If they make any more it should be a blank slate, and possibly use the disney characters and use their worlds to make original stories(which could go horribly horribly wrong...)
TWEWY: This is by far my favorite DS game, maybe it is the XL you played it on(I played it on lite), but I had absolutely no problems with the combat system. I found it rather engaging to go back and forth and it kept me in battles more than most other RPG battle system. It's basically I had to pay attention or I would die. The setting of the game was great, I'll admit Neku was a little whiny at the beginning but after seeing what is really going on and after all the plot twists, it was rather a unique and amazing story that isn't really seen that much.