My K5 Blazer and my lil S-10 4x4 Blazer have both done well with sets of BFG T/A KOs, love em, on my 2nd set with the S-10; ran BFG Long Trail T/A Tour's on my GMC Envoy for winter but am changing them out this week and running a set of Yokohama Parada Spec-X performance tires for summer.
Nitto Terra Grapplers dont last for ****. I wore a set out in 8 months on my service truck in south Texas. Nothing but Dueler AT Revo 2 tires for me now.
I've run a lot of Coopers and I'm on my second set with my current truck - purchased in December @ 83K on the truck . Would have run the old set of Coopers a little longer, but I busted one during deer season @ Honobia on a sharp rock. That set had about 40K with quite a bit of off-road in rocky terrain. It's a 2008 Z-71 4-door.
Toyo AT II's on our JK, good on the highway and good off-road. Been in some deep mud and they clean out ok for an all-terrain tire. They handled good on the rocks at Disney and on the Colorado trails. Any all-terrain tire is going to be compromise but these seem to be pretty good.
the general grabber AT2 is an amazing tire...read the reviews...it looks a lot like the BFG A/T but it is cheaper and quieter in my opinion...for a Z71, I'd at least get them in "Extra load" or Load "C"....do not do load range "E" though or they may ride too stiff...that is good advice for ANY truck tire you get.
BFG AT also. I decided to run coopers AT's this last time because they were cheaper and they perform well, especially off road but are a little noisy after 8k miles. When these wear out I will go back to the BFG's.
I'm using Goodyear silent armors on the rear of my 2wd truck(they don't say AT but they do really well). I've had the toyo at's in the past but they wore out in the middle and too fast. I have the Goodyear Duratrac's on my 05 Wrangler but I've heard they wear fast if you drive gravel daily. If I were more worried about the price I would get the General grabber AT2's.
When I was researching for my truck, it came down to Terra Grapplers vs BFG ATs. The BFGs seemed like the longer lasting tire, but the Nittos were considerably cheaper. I ran the math and, based on average usage and my driving, they almost home even. I got a great deal on my nittos, so that made it a no brainer. My nittos have been great, so I recommend them, but the BFGs are also great. Pick the one that fits your wallet best.
General Grabbers were also in the running. I can't remember why I ruled them out. I never heard a bad word about them. Maybe it was cost, longevity or appearance.