Tons of stuff here.
Bookcliffs: Rolling desert, fast twisty singletrack, some ridge running. Plenty of loops to connect for good mileage.
Kokopelli: More rocks and ledges, overlooking the Colorado River (read: scenic). Again, lots of loops for connecting and adding mileage.
Tabaguache/Lunch Loop: Some great techy singeltrack stuff coming off a "main vein" of doubletrack with lots of loops to connect and add mileage. Even some "shuttles" that include plenty of climbing.
Rabbit Valley: Lots of moto trails, some are great fun. A superb area after rain, lots of views, and a mix of all sorts of stuff (doubletrack, singletrack, rolling, ledges, rocks, etc). And the familiar option to connect loops for some big miles.