(edit)Rock and Metal are my fav's of "mainstream", and I like me some DJ Shadow. Not as familiar with mainstream shit honestly. At least to me, VGM is truly what keeps musac alive. The most creative aspects of it anyhow. BTW, I submitted an entry. Hope you like.
(edit2)
As a caveat I'm well aware that VGM draws from more conventional (and otherwise) sources, but I mean, I may as well be saying the grass is green and the sky is made of Mountain Dew. Mmmm Diabeetus.