just started to actually really enjoy sours. I would HIGHLY recommend any of the barrel aged sours coming out of Russian River brewing, or anything from them really.
The best sour I've ever had though, and the one that broke the ice on the style for me, isn't available in bottles. If you are ever in Boulder, CO, make sure to stop by the Avery Brewing Co. Tap Room and try the Eremita. They just did their second batch of it, and it is truly amazing.