Ah, tough question. Music does more for the games atmosphere for me, so I'll go with music.

Music.

I don't feel graphics in my bones. Graphics don't make me dance. Graphics don't get awesome remixes. The music can change the mood from scene to scene in a game. Most games don't change up their graphics at any point.

Music.

well music is probably one of my favorite things about the game

and my personaly favorite 

and this one pretty good to. 

WTF why are so many people saying music?

Graphics by a mile. Music can suck my nuts.

music easily, the music in classics like Super Mario Bros. or The Legend Of Zelda is great and stands the test of time, while this gen's graphics will look terrible next gen.

I suppose music has a higher ceiling than graphics do for some, but I can't really see the answer being anything but graphics. Without graphics, you don't have a game. Would you rather play a game blind or deaf? 

Defiantly music.

Would you rather watch a movie on mute or listen to the book-on-tape version?  What's more important, seeing a guy's lips move, or hearing what he has to say?

No matter how good graphics can get, you can't have a room full of people humming along to the graphics.  They can all do that to the Mario theme from 1985.  Music, like most gaming, is more of a social activity than visual art.  You can even have entire games based on playing with the music, like Parappa the Rappa, Rock Band, Just Dance, Audiosurf, BIT.TRIP BEAT, and Elite Beat Agents.

Why are people saying graphics aren't timeless, when they certainly are. Just because they are not technologically impressive doesn't mean they can't look good, and there are games from all generations that can prove it.

But again, if this discussion is about the sofistication of the technology rendering the image, rather than the image itself (which I still don't know if it is), then there isn't much point discussing it, as it is rather pointless.