Well, I have some I like, mostly from Black 2/White 2. But before I start. I HATE that western sounding route. It like plays on EVERY route...and it's just...dull. Bleh.
Everything about the New Team Plasma. I mean, there's no comparsion with the old they were just straight up more better.
The Elite Four battle theme. Eh, I like this on from the first game. The battle theme is Hoenn-ish. They should stick with giving the Elite Four member music different from the gym leaders.
PWT final round battle theme. Make me think of Kirby. :p
Elesa Gym theme. Dat took me by surprise when I first heard and I love how more music is add everytime you beat a Gym Trainer.
Colress battle theme. This has to my favorite one outta all of'em.
Route 22. The best sounding route on the game. It sounds similiar too a route from Pokemon R/S/E. Too bad you'll first hear it when you reach the last gym leader's city. *sighs*