Trails: Eastern Pennsylvania, decent combination of rocky and hardpack, rare mud, and occasional sandy soil, especially in the winter.
I used to run the Nevegals, then a Nevegal front and a Small Block 8 in the rear. I hadn't realized just how damn slow-rolling the Nevs were until I switched off of them to something else. I've never needed the level of traction they provide, so I doubt I'll be running them again - surprisingly slow tires.
The SB8s are nice, especially when I was on a team where we could get them for a pro deal. The Slant Six is a pretty decent tire, I was running that up front with a SB8 in the rear for a while. That worked nicely.
Zero experience with anything Maxxis.
Have run Schwalbe tires, with my favorite being the Racing Ralph 2.4s - running a pair of those on my hardtail (coming directly off Nevegals) felt remarkably fast. Traction was good for such a fast tire. Have also run Rocket Rons which worked pretty well but wore crazy fast.
I know a bunch of guys who swear by the Saguaro - I picked one up once, and managed to tear a 1.5" gash right through the tread on my first ride. Haven't bothered to try it again, but I should. Several folks have told me to stay the hell away from the TNT tubeless-ready version as it is brutal to get on and off. I had run a well-used one on a spare wheel for a while, and actually wound up cutting the tire off the rim to get the damn thing off.
Currently my wife and I are running Continentals. For the winter, she's on the X-King Race Sport in the rear with a Mountain King Race Sport in the front - during the summer months she's been on X-Kings front and rear. She ran the Race King Race Sport (these names, yikes!) for a while but didn't like the traction in powder over hardpack. I, however, love the Race King, but at nearly 2x her weight, I run all of my tires with the ProTection sidewalls.