Throughout their history of over 15 years, the Pokemon games have produced some awesome soundtracks in each generation, some recurring and some new.
My favourite recurring themes are the Opening theme (imo, B2/W2's version was the best) and the Pokemon Center theme (imo, X/Y's version was the best).
For DPPt, my favourite themes are the Bicycle theme, the Battle Tower theme, and Giratina's battle music in Platinum.
For HGSS, the music that plays in the Sinjoh ruins, as well as the music that plays when Arceus makes the egg, were cool.
For BW, I don't remember much because I played mostly with the sound off, but I recall that N's theme was good.
For XY, the Gym Leader battle and the Kanto Legendary battle themes were awesome. And, Sycamore's Lab theme was beautiful.
Oh, I almost forgot, Lavender Town's theme from Pokemon R/G/B was amazing.
So, what's your favourite Pokemon game music?