WILD
Or Wilder.
Assuming you mean over pointing dogs, Greater Prairie Chickens.
Their cousins, the Ruffed grouse require the same dog work, but less range (a dog with a great nose, that locks up at first scent). The timber grouse actually tend to hold a little longer, for an experienced dog. Prairie hunting, for any of the three pasture grouse, provides a wonderful opportunity to watch dogs work large hillsides, and evaluate their style. All three are delicious, which is a plus.
Wild Bobwhites offer a chance for lots of dog work, if numbers are decent, and a frosty covey rise is more exciting than most women.
Pheasant are great fun over flushing dogs, or the best pointing dog you've ever owned, if you stick to cold days, or deep, narrow cover.
In pen raised birds, either planted, or early release, Chukar generally win out.
Sooooooo.......
I guess the real answer, for me, is, which ever bird I can hunt tomorrow morning.