Listen to Radiohead - how to disapeer completely and around 3:00-3:20 you can hear music from the original phantasy star. Also in Hellbound by eminem you hear audio clips from soul calibur. Just the ramblings of a madman
I think Rahzel uses some Street Fighter samples in one of his songs, and of course there's the delightful "Proto Culture" by Deltron 3030.
The best use of videogame music in a popular song would be the encounter with the cracked-out Pac-Man in the Bloodhound Gang's 'Mope'. :-D
My friend had an a song by some obscure rapper that pilfered an entire trcak from FFVII. The one that plays when you're at the deserted city of the Anichents.
oh btw, I doubt if anyone knows them, but Dutch rap pioneers Osdorp Posse have a song on their "Geendagsvlieg" album that ends with a song from Command & Conquer
http://www.starblast.org/starsongs/crapintime.mp3 the song is called Back In Time but the original title is as the filename Crap In Time.
Radiohead does do this a lot - for example, in "Let Down", there are lots of samples (especially, in the middle and the end) that they themselves programmed on their Spectrums. The samples begin at 3:30 and 4:41 in that one. I don't really remember where I read this, though. Irm sure many people here have listened to "the Minibosses"? They rock so very much. They play old 8-bit NES songs but instead of synth they use electric guitar and other "organic" instruments. Ah, and in Latin VH1, there's recently been a video, a cover from an Argentinian hit of the 80s called Juegos de Amor (games of love). I think the ones performing the cover are Moenia. The video features a young couple playing Pong with the stars in the sky as a screen. I think they switch to Pacman later in the song.
UK band "Dragonforce" is using various game themes in their songs like themes from Last Ninja ... I talked to Herman Li (one of the guitarists) after one of their shows, and he is really into videogames ...