BFG a/t is good snow and ice, and awesome on road, but horrible in the mud. I still like them though.
I hear a lot of people say that...
But my dad found them next to worthless on his F-150 in the winter. And a couple years ago I watched someone trailriding with 'em and they loaded up and he slid backwards down a hill into a tree, smashing his back bumper and tailgate.
As far as an everyday tire, I usually look for a very aggressive AT tire, something that's borderline mud tread, has big cleats, siping, and a good bit of open space between the lugs. Last set I got were Sport King AT tires, and I got around 50k out of 'em on my Ranger and they did impress me with their performance. I had them in rain, snow, mud, and on hardpack snow an ice, and if it wasn't that they went up a good deal in price, I wouldn't think twice to buy 'em again. (I may still get another set anyway). Little hum on the highway, but they suited my purposes so I wasn't going to complain.
I did find that pure mud tires don't like ice much without chains or studs. But if you can fight a set of chains on over the lugs of a regular mud terrain, you now practically have a tank. I drove my 2wd Ranger like that for awhile when I was off at college, I could plow through snow up over my hood like it was dry pavement... and with only about 200lbs in the bed.