2″ Bonty Mud X’s front and rear for tyres that work well in pretty much any muddy conditions (though the heaviest of clay muds will stick to ANY tyre and cause it to clog up, trust me!). They also work well when the conditions are a bit firmer too, something which the Panaracer Trailrakers (though exceptional in mud) don’t!
Or 2.2″ Bonty ACX’s if you just want a good “all conditions” tyre that happens to work well in mud too. I’ve got the 2.35″ (quite a bit bigger than the 2.2) on my Full sus bike, and they’re bloody grippy in the slippy stuff despite not being a “proper” mud tyre.