Ooh, I love a lot of game music. ^^
Generic Route music -- Fr/Lg: The original in R/B/Y wasn't bad, but I like the remix better.
Wild Pokemon Battle -- Fr/Lg: Vastly superior to the Wild Pokemon Battle music in either Johto or Kanto. The G/S/C remix burns my ears, though. ><
Trainer Battle -- Fr/Lg: Again, IMO the Kanto Trainer Battle music is way better than Johto or Hoenn. The makers of G/S/C should have just stuck with the original music during the Kanto quest part because they did a sad job with the remixes.
Celadon Hideout -- Fr/Lg: Another awesome remix of a classic R/B/Y tune.
Route 12-15 -- Fr/Lg: Wasn't bad even in R/B/Y, although the remix in G/S/C was horrid. Fortunately, the Fr/Lg remix was even better than the original
Lake of Rage -- G/S/C I actually like this music better than the Fr/Lg remix on some of the Sevii Islands. I dunno, it just has a more epic feel in the metal games.
Mahogany Hideout -- G/S/C: This music is just plain bizarre, but ya gotta love it. XP
Legendary Beast Battle- C: The best battle music ever. Period. I was sad after I finally managed to snag all three of them because I couldn't listen to it anymore. :P
Sky Pillar -- R/S/E: Sometimes I just go to the Sky Pillar, hold the game to my ear and enjoy for several minutes. XD
Regi Battle -- R/S/E: I don't like the Regis, but their battle music pwns.
Rayquaza Battle -- R/S Pinball: And I mean pinball--this track is a remix of the Groudon/Kyogre/Rayquaza Battle in R/S/E, only faster and way cooler.
~Chibi~