Erm- the Super Mario Brother original theme brings back memories- so its gotta be that! Although I do like Mindas (can't spell the name!) song from Zelda Twilight Princess.
I like the Mario theme just because I can play it on the guitar but my fave music has to be the original Monkey Island theme.
All the famous nintendo music. Let's see... Tetris. SMB1, 2, 3. All Zelda's especially OoT, and TP's Hyrule Fields. Oh, I forgot, DK RAP!