If you can get the Surly lineup, they make the best canned beers I've tried, but unfortunately, they aren't available in the VA/DC/MD/PA/NC/WV area that I hike in most of the time. We've got a lot of canned beer options, and I've tried most of them. The Oskar Blues varieties are still the winners in terms of what is readily available, but canned Guinness and Bodingtons aren't bad options, either, when Oskar Blues isn't available.
That said, I'm far more likely to pack in a tiny plastic bottle of an Irish cream or a sipping tequilla than I am to carry beer on the trail. For group trips, those tiny juice boxes of wine are pretty good options -- Target (in my area at least) carries a line of those wines that are above average. The Merlot, in particular, stands out.
Sorry ... didn't mean to thread drift. Back on topic, beer in cans: Surly if you can get it, Oskar Blues as a close runner up.