Here's one that I think really flies under the radar as a good, relatively inexpensive (you can always do some upgrading) option for all the off pavement options.
I think that Cannondale is missing a large portion of riders because it's marketed in the "Recreation & Urban" bikes section. "Real" riders wouldn't ride a rec bike....
It's aluminum, which may be a little harsh in bumpy, but that headshock provides a nice little cushion and control for rough downhills.
For $1600, not a bad option for many though.
http://www.cannondale.com/catalog/product/view/id/31186/s/quick-cx-1/category/935/