I really like chiptune, so I go back to listen to a lot of various tunes from certain 8-bit games. However, the "little diddy" format, like for the Pokemon Bicycle theme don't have too much staying power for me. Chiptune has grown up a lot over the past few decades, to be able to encompass songs of all sorts, not just nostalgia candy.
Tower of Heaven is this 8-bit flash game that, while having a multiple-versions-of-the-same-theme soundtrack, hosts some of my favorite video game music period. Even though I'm TERRIBLE at the actual game.
And, of course, there's Silent Hill's music, even though I always feel a bit crummy and paranoid after hearing the music...
Also, Halo.
Yes, Halo. Everyone seems to forget that Halo: CE actually had a great, percussive, ambient soundtrack.
Of course, when it became a hit and the music people got a budget beyond synthesizers, they're all like, "To hell with that! People only remembered the electric guitar and orchestral swells! Let's do more of those instead."