I also liked the theme "Infiltrating Shinra Tower". Summoned Beast Battle wasn't composed by Nobuo Uematsu, it was by Junya Nakano. My 3 least favorite songs by Uematsu:

3rd: Double Question Marks (??) (FFVI) - this song is just annoying and boring. It has a short drum part to create some variety, but after that, it goes back to the annoying part again.

2nd: What (FFV) - Similar to "??", except it's even more repetitive, which makes it even more annoying a song than "??", IMHO.

1st: Djose Temple (FFX) - Okay, I know this is quite an experimental song, but I just don't like this track at all. The strings in the beginning are quite annoying, and the song has a few random notes after that, and it doesn't really have any direction. The song sounds pretty much like a mess from a chaotic nightmare to me, and it wasn't even designed for that kind of scenes in the game.

There are some FF songs that I think are quite dry, but unlike these, I don't think they're that annoying. "Ceremony for the gods" from FFIX was quite annoying with those high-pitched instruments, but at least that song worked with the comic scenes where it played.