I've got two that go hand in hand.
Intro Theme for "The Legend of Zelda"
Between the ages of 3 and 4, I spent my time either playing in the creek of my apartments, watching VHS tapes from my dad's movie collection, or playing NES. I remember spending about as much time just listening to the music and letting it play for long periods of time as I did actually playing games. This one in particular can still give me goosebumps. I used to stick my ear up against the speaker of the TV and let those leaping bass notes do their damage to my eardrum. This music was the first time I remember hearing harmonies that off-set each other slightly. I didn't know WHAT it was, but I knew I liked it and it made me feel powerful and centered. The way the first high melody plays almost sheepishly and in a shy way only to be shadowed by another sheepish and small, but deeper melody for a few measures before coming together and making one strong, epic unit of music. As a kid, it just gave me a soul boner, but as an adult, I find that it perfectly complements the idea behind the game. You start off as a weak, pennyless, unarmed elf boy, but as you gather items, weapons, and the triforce pieces, you become stronger and more able to do what must be done. I didn't know anything about music, but I felt like the music was somehow a piece of me. Like when I was created, the music was there with me already. The game itself came out in 1986 and both my parents played the Nintendo that was in my room, so I imagine I heard this music a lot before even having memories.
https://www.youtube.com/watch?v=uyMKWJ5e1kg
This next one you will want to listen to from start until 1:30 in... as the first three songs are all great.
Castlevania 2: Simon's Quest OST
This was yet another game where I would start the game, just to let it play in the background. The music and the scenery are perfectly harmonized into a Gothic architecture. I grew up on horror films and this game was the first one I was ever exposed to that felt familiar as a horror genre. The soundtrack goes through slow and creeping tunes, to fast and energizing ones. If the bass isn't going fast, the keyboard/guitar parts are. The sound effects to this game are programmed into my phone as ringtones and texts; have been for years, and I am still not tired of the music. The faster beats in this soundtrack inspired me to rock my jaw from side to side with the notes to make a sort of drumming effects in my head. I had no real way of expressing my love of music yet at this time except for singing specials for churches, which did not give me the same sort of high this other music did.
https://www.youtube.com/watch?v=U1VNQRQ6wfc