Probably a fairly predictable response but the BGM that plays on Route 1 in RBY. I grew up with gen 1, and heading out to Route 1 for the first time way back then felt like the beginning of an amazing adventure. Yeah I know, there really wasn't anything all that amazing about the graphics or sound on the GB, but this was during the time of Pokemania, so it's hard to put into words the excitement I felt hopping into the world of Pokemon, and getting a chance to catch the Pokemon I wanted the most and to be able to take on the gym challenge, as well as battle my friends. Really was a magical time in my childhood and BGM like this one helps me relive some of that magic through memories, and it's a very cozy feeling.
https://www.youtube.com/watch?v=u0G12EBW4KY&list=PL61B646ED7B059AEB&index=3 
