Mack Ridge is definitely one of the good ones. When combined with Troybuilt, it makes a great loop for an afternoon ride. It comes out to about 13 or 14 miles and has plenty of fun stuff and great views. I like it best riding from east to west, though it is close.
Going east to west, you start with a good, intermediate climb. There are some fun rocks to play on and enough technical stuff to keep you interested. Really fit people can ride this on a single speed. There are a few nasty "hike-a-bike" sections that you'll need to climb up. You'll see them in the photos. The view from the top is wonderful. Riding this will make you want to ride Handcuffs. You'll see how cool the ride is and want to drop down to it. Combine Troybuilt, Mack Ridge and Handcuffs for a little longer ride.