Forgive me if I missed a few thoughts already posted here-
Sturgis is hard to beat for promance and History and beauty.
Sturgis is in the middle of the country for a reason, its the middle, almost.
Next, it provides some of the most beautiful roads for a tour whilst there!
If you travel all of them you truly take home away inundated with amazement!
Irongate, Crazy Horse, Rushmore, Deadwood, Spearfish Canyon, Devils Tower etc.
A lot of History there.
Next, we have these bikes because we like to ride. Tour.
There is no such thing as too far, in fact, to close would be less than interesting.
Pick a great place, who would not come?