An open question. Whenever I hear a theme tune from any N64 or earlier Nintendo first-party game, I get somewhat emotional and nostalgic. What made their music more memorable and catchy than other games, and why did including several hundred classic tunes in Brawl make it so much more awesome?

Everyone knows the Super Mario Bros. theme and Pokemon route music...

They can re-mix they're tunes like no other? :D That's honestly it for me xD Anytime I hear a new song from Nintendo it always blows over and I forget about it, but when I hear a remixed tune, back from the MIDI days, (where songs were so simple they just had to get stuck in your head), I get the feeling that I'm playing a continuation of a series. And most of Nintendo's biggest franchises are part of a fairly lengthy saga that spans through video game history (Mario galaxy using remixed tunes from the original Mario Bros :P)

 I feel exactly the same.....

They're just simple hook based tunes that are repeated a lot throughout their respective games/series.

The Pokécenter music is permanently etched onto my brain, to the point that it actually bothers me to hear remixes of it, somehow it's like sacrilegious or something. And it's not some childhood memory, I first played Pokémon when I was 25 years old!

I don't know what the secret is, I suspect part is talented people writing the music, and the other part is that the actual games are so good - we played them so much, we can't help but remember the music.

Depends a lot of the composer but I find any Koji Kondo job very enjoyable...

I think the music of a game becomes memorable when a game is a great one. Anytime I've played a game a lot, the music automatically became great to me. There were some games I loved that the music was merely good but because I played the game so often, it becomes special. And since so many Nintendo games are great, the same applies. Although Nintendo games almost always have great music too.