I have always used Michelin Deserts on my race bikes, but have also used both the T63 and Dunlop 908RR over the years too... (on my XR650R).
I'd say the 908RR rear is a great dual-sport (ie. road and trail use) tyre, having ridden one from the UK to Morocco and back as far as Northern Spain before it was worn out.
I've also used T63s (front and rear) on the XR, and found they were pretty useless by about 1000 miles - I wouldn't recommend them on a big heavy/powerful bike - the Deserts will really last twice as long...
However, if you are on a budget - as a previous poster suggested, the T63 rear is similar to the Michelin Desert rear... while I'd add that the Michelin AC10 front is a very similar tread pattern to the Desert front - all are DoT street legal tyres.