Actually I would say the area Woodchick was in is in the top 5 easy. Great riding out there where Oregon/California/Nevada/Idaho converge. Especially if you arent fond of mud and trees.
downieville is truly great riding. now imagine it being 75 times as big. and take out all the mtb weenies. and imagine the trails got about 1/10 the use. and then make the trails narrower. and especially remove the chp wiener that hassles motorcycles on the road trying to connect trails. moab is in eastern utah, just off of interstate 70.
Downieville is by far my favorite place I've ridden, of course I've never ridden Idaho. This thread would be taboo on that other site.