Of course there's many others too but my problem is I'm always taking someone new to the area so I hit all the highlights and never try new stuff myself. For instance Rhythm and Blues is a twisty 3 mile singletrack that rides like it's closer to 7, all stuffed into a smaller area. It's like you're doing a self propelled roller coaster with constant up & downs but less than 200' of elevation gain. Like everything else out there, it will feel like much more. We usually do it as a twilight ride when we feel like riding but don't have a lot of time.
Then check out the Boy Scout Trails (photos below) closer to I-15 in Hurricane, Zen in St George and I've been told Kentucky Lucky Chicken is techy as well.