Yuengling has always been the standard beer in my area so it got me into good tasting beer. When your first beer is a yuegling you never care to drink bmc. Troegs Hopback is the beer that really changed my life.
A couple of beers from Yazoo Brewery in Nashville -- their pale ale and Hop Project series. Downed a lot of those and eventually came to the realization that I'd like to try making my own beers... Thanks, Yazoo! Wish I still lived around there.