i like 21, mostly because its close to my home and holds plenty of great deer, and prolly more than a few in the 100+ range, its a huge unit as well, with plenty of areas that are good. maybe even check out ole 6a,there are lots of good whitetail near beaver creek
bloody basin near the verde is good
near chasm creek down salt mine rd in camp verde is good( if you get away from the road)
crossing the river at childs,or coming down from pine mountain close to the river is good
some spots on the agua fria are good
i think pretty much anywhere along the verde rim is good, i personally dont care for dugas rd or the squaw peak area, theres plenty of good deer but lots of people chasing them