I'll admit it--I don't have one. I enjoy picking out new types of microbrews just to have my own little taste test.
Sierra Nevada Pale Ale is probably the closest I have a favorite beer.
Sometimes it depends on where I am and what I am doing. In Canada, I gotta have LaBatts Blue. Reminds me of old times. In the Bahamas, Carib was the best beer evah! Playing poker, while I can't usually stand lite beer, Coronna Lite with a wedge of lime ain't half bad. When I'm feeling particularly manly, I love "Hop Pockets." Bells Ale out of Kalamazoo Michigan is great when you can find it.
Two last confessions. I am a beer snob. I can barely tolerate the regular beers such as Bud, Miller and Coors. Only drink them if they are the only beer in town. Oh, yeah, and for a cheap buzz, I highly recommend "Steele Reserve." Taste pretty good, but kicks like a mule, so watch yourself...