Any songs where it's amazing or perfect... except for that one part that sticks out like a sore thumb?

Yaught - Paradise Engineering.

Bring in the retro synth, introduce a slapping bass beat, and just when you're ready for a shot of adrenalin in comes the overraught, out of tempo, spoken word over the top.

:-(

Similarly, every Mogwai album has to have a synth-voice track for some reason. Presumably to give the audience a chance to go to the loo without missing anything.