"Best $2k I Ever Spent!" Robyn, Russell Brand & More Party At Katy Perry's Wild West Ho Down Throwdown Birthday

Quick: who's the celebrity you would most want to be best friends with? Just a guess, but unless you're a 21-year old gay man or a 12-year old girl, you probably didn't say Katy Perry. However, that might be your loss, based on these photos of the rollicking Wild West Ho Down Throwdown that Katy and her future babydaddy Russell Brand threw last Friday to celebrate her 27th birthday. Actually, I might even have to change my own answer to that "best friends" question. Sorry, Joan Didion![all photos via The Cobra Snake]