Kenda K270
Very popular and inexpensive. Wears very well (5k miles or more).
Soft sidewalls, be careful at low pressures. Decent offroad traction.
Knobs are flexible, making the tires feel squirmy on the street.
Some people don't like that, but others get used to it and have even scraped
pegs with them (accidentally!). You can use either the 3 or 3.25"
front; the 3.25 may help flotation in sand, but will slow down the steering
on the street. The 3" is cheaper.
Kenda K761
More street oriented than the K270, and also popular. At the
time of this writing, this was the most popular D/S tire at Rider Valley
Motorcycles. Quiet, and hooks up well.
Metzler MCE Karoo
My personal favorite, although to be fair, I haven't tried the D606
or MT21. Relatively stiff sidewalls, so you may be able to air down
more than usual. Despite the aggressive knobs, the tire handles great
on the street as well. New tires feel like they want to "fall off"
of a straight path, and stabilize in turns. This goes away after
100 miles or so. 3-4k miles rear, roughly twice that for front.
May be able to get more if you continue riding strictly on the street.
Dunlop D604
Replaced by the D607.
Michelin Anakee
Uses silica rather than carbon black in the compound.
Kenda Trakmaster
Rears are very good, great traction in loose terrain when new and aired
down. Get about 3k miles before they are useless offroad. Fronts
are very sketchy on the street, and don't seem to have much cornering traction
offroad.
Pirelli Scorpion Pro (Was MT-83)
Front is better than Kenda K760 Trakmaster
Pirelli Scorpion (street)
Great street tires, one owner got over 15k. Good on gravel roads
if aired down to 20 psi, but not recommended on anything worse.
Offroad combos:
Dunlop D606 front, Kenda K760 Trakmaster rear