www.songstuff.com - many different artists and styles here. There is a forum where you can comment on songs and lyrics.
www.soundlift.com - huge choice of artists on here, with styles ranging from rock, to rap, to classical. You can also watch music videos, and a chart is updated every day of all the songs.
www.vai.com - Steve Vai's official website, with info, lessons, tips, tour dates, videos, forums etc.