At the Examiner, Charlie Papzian has a brief article about some taste tests he did in several Western cities. A typical outcome:
In Arizona 100 beer enthusiasts and their friends and spouses turned up at the Pusch Ridge Brewing Company and Pub. Another beer tasting was held. The results: Sam Adams 42 versus Corona 3; bottled Sierra Nevada Pale Ale 27 versus Bass Ale on draft 19; Guinness on Draft 1 (that is correct, 1) versus Pusch Ridge Old Pueblo Stout 47.
The tests were apparently not just among beer geeks; some Corona and Guinness drinkers were converted. When this do this sort of thing with wine, the punchline is usually Gallo beat out some pricey Burgundy, or something like that. So this is nice to hear.