I could be wrong, as I'm not any sort of 'nu metal' expert ... personally, I wouldn't ever consider Godsmack as nu metal. Maybe their early hit Whatever touched on it, but I just recently listened to their '98 debut album and most of it doesn't seem to fit that label. But, again, I could be wrong. I do like much of Godsmack's material, so if they are nu metal, then they'd definitely be my favorite.
The only band that I ever associated as nu metal that I didn't mind was select tracks from Limp Bizkit (maybe about a half dozen or so). Never liked Rage or Korn (or much of anything else).