Number one for me is Queens of the Stone Age. Favorite stuff other than them from the last month or so switches between Airbourne, Monster Truck, Orianthi, Toseland, Alter Bridge, Joe Satch, CCR, Two Steps from Hell, Dead Mau5, Knife Party, Feed me, Celldweller, Zero 7 and Bonobo.
Other than those, my Spotify account is covered with all manner of stuff, last few stared songs are from One Republic, Arctic Monkeys, The Pretty Reckless, Reckless Love, Crashdiet, Cee Lo and Spiderbait.