I've been partial to bringing a couple beers with me to drink during longer, non-singletrack rides. I've also been buying canned beer almost exclusively for the last couple years, which is much better suited to bike transport than bottled beer. Canned beer has really won me over... no broken glass to worry about, the cans are easily crushed and carried after they've been emptied, and some breweries out there are making really good canned beer.
My current favorites are New Belgium Fat Tire, and most of the Surly offerings... good stuff.
I don't drink that much or all that regularly, so I don't really care to drink cheap, watery beer. And I don't buy into the idea that it's cool and hip to drink crappy beer. Sorry buddy, but that can of PBR doesn't give you any street cred' when you're standing next to your over-priced bike decked out with carbon fiber and $700 wheels.
Stopping can be as much fun as riding...