Well, when you have almost no flavor to begin with, its not too hard to make another beer that tastes like it.
With the sale of A-B, the Boston Beer Company is now the largest U.S. owned brewery. I personally hate the Sam Adams beers as well, but I can at least appreciate them selling hops to the brewers who are more at liberty to produce the tasty beers. They also at least try different styles, and try to push the limits with beers like Utopia and Triple Bock.
Yuengling is 2nd (not a lager fan), with Sierra Nevada in 3rd (mmmm, Bigfoot).
Sierra Nevada can make some stinkers (Southern Hemisphere this year lacked of flavor), but they're the best "big" brewery in the US. Of course, I put big in quotes here, because they still only ship 700,000 barrels a year (compared to Sam Adams at 1.3 million and Yuengling at 1.2 million). Still, they're huge compared to great smaller craft-breweries, like Dogfish Head (39,000), Avery (13,000), Abita (75,000), AleSmith (not sure, not a wide distribution), Three Floyds (4800), Real Ale (only Texas), Saint Arnold (only Texas), etc.
Any preference on beer styles? I'll try to grab some brews you can't get on the east coast for the Bills game.