Originally Posted by Nowwhat
mostly you only need a front knobby...
Go with a Dunlop 606 on the front and any dual sport tire on the back
Other good choices:
Pirelli Scorpion Rally - excellent, good price
Michelin T63 - really good dualsport tire, great price
Conti TKC80 - a perenial favorite, spendy
Pirelli MT21 - kind of old-tech but very popular
Kenda Trackmaster - not so good on-road, but great off
Metzeler Karoo2 - good on but not great off
There are probably more but these are the common and popular ones.