I second that Deschutes recommendation. Black Butte Porter used to be my favorite beer -- so much so that I actually made a side-trip to Bend, Oregon to visit the brewery on a road trip.

My favorite these days is Fat Tire Ale by New Belguim Brewing Co. in Fort Collins, Colorado. It used to be very hard to find in California until recently. Now I can get it at Whole Foods and Costco.

Incidentally, with both Black Butte and Fat Tire, I prefer bottled to draught.