I don't know how I never noticed this thread until now. My absolute hands down favorite domestic brew is Yeungling (Lager... years ago they made an Ale that I liked just as much). And the Yeungling brewery in Pottsville, PA is a very fun tour - totally different from the others I went to. They have a network of underground caves where they used to store the beer before refrigeration existed.
I'm also a fan of most Sam Adams flavors (especially Octoberfest, but ESPECIALLY Cherry Wheat), anything Magic Hat (another interesting brewery), and anything cheap and light enough to drink quickly out of red solo cups with a large group of friends....
As far as foreign beer, I've been into Heinekin in recent months. In college I was very fond of Killians Irish Red.