Its one of the best beers that is available nationwide. Otherwise, your choices are Bud, Miller, and coors products. There's only a couple microbreweries that are in all 50 states, and Sam Adams is one of them, Sierra Nevada *might* be, but I'm not sure. Very few microbreweries distribute everywhere. There's nothing wrong with their Boston Lager, Winter Lager, or Octoberfest. I like all 3 of those quite a bit, sure there are better local beers out there, but those are all solid choices.
Also obligatory
The Beer Threadbefore we derail too far