The tires that were on my truck when I adopted it were General Tire Grabber TR 235/85R16 E, although they have a M+S rating I had to use 4HI to reverse out of parking stall with only an inch of snow on the ground(extremely embarassing). The tires still had 80% tread. I had originaly planned to wait until they were down to 60%, but that incident quickly changed that.
I have usually gone with Bridgestone Duellers but this time I was comparing the Bridgestone Revos and the BFGoodrich All Terain T/A KOs. After a long process of research/road testing/asking other drivers for input I settled on the BFGs.
The BFGs have more road noise(noise for me is not an issue,I love my diesel!), The Revos are probably better on the highway for MPG, with the BFGs I still average 26mpg hwy/16mpg city. Off road traction with the BFGs is awsome,heavy rain/snow/mud no problems what so ever. The BFGs are also severe snow rated, one of only a handful to get this rating.
My truck has a 13500 GCVW rating and when I have had it loaded the BFGs have proven their capabilities. So far with 8000 miles they have shown no wear.
The only other tire I would consider and/or recommend would be the Michelin LTX M/S if the majority of your driving is highway, (smoother and quieter).
Just my two cents