AC/DC is great.. but they're kind of a band that you listen to for a while and then get sick of it until next year. I play Appetite For Destruction probably once a week. AC/DC's songs also have a tendency to sound the same, whereas Guns & Roses has a good variety of waves.
The unholy trinity of 'Jungle', 'Paradise', and 'Child' is greater than anything AC/DC has put out, in my opinion.
GN'R ! AC/DC can be a fun band and all, but musically, GN'R's songs were superior . Most of AC/DC's songs are founded on 3 power chords, while GN'R can deliver a raw rock n' roll sound with complexity and lyricism. Appetite For Destruction is legendary, and their finest work, but the Illusion Albums and Lies are both great albums as well. If you look back on the quality of music on those 3 albums, combined with the total package of Appetite For Destruction, you'll see why GN'R should win this one.