R/B/Y's Lavender Tower music is awesome. It's dramatic but not so terrifying you feel like something's going to pop out at you. R/B/Y's Lavender Town music is good, but, it's creepy as heck. :[ Plus, it gets stuck in your head for days. And there's those rumors about kids going psychotic and killing themselves because of it, which, probably isn't true, but... still, it's creepy. :[
SNOWPOINT CITY!
Goldenrod is nice. Violet City in HG/SS is awesome. It's so carefree and relaxing, yet something about the beginning is kind of dark as well.
Ecruteak and Bellsprout Tower are both great. They did an awesome job making them both sound ancient and sacred.
R/B/Y's Silph Co music is pretty cool.
And basically all the music from the latest games have all been outstanding. :3