Deer Crest is a good trail up or down. Though it's more fun going downhill, it's a good option if you want to ride uphill and avoid paying for the lift (the other option is Tour Des Homes, which is considerably less interesting).
In either direction, you'll find mostly smooth, comfortable singletrack: not too skinny, not too wide, not too rocky or rooty, but just enough small obstacles to keep it interesting. There are short sections of dirt road, but all intersections are well marked. Some sections are exposed on a hot slope while other bits are in deep forest, but this area is generally hotter and drier than most of the trails to the east in Deer Valley and Park City.
Downhill, this one flows perfectly, with nice berms and good traction the whole way.