Depends on if you're going out there to ride or party. Looking to tent camp or something better? If you're going out there mostly to ride, Piedmont is a good option. It's half-way between Sturgis & Rapid City, close enough to all of the action yet far enough away to get some sleep at night. Below is the information for where I stayed last year (as well as my whole group plus a couple other guys from this forum). It worked out really well. Good luck. Also note, prices where from last year.
Piedmont Rancheria (also called the Horse Ranch)
Edgar (Ed) Lamkin
I-90 between exits 44 & 46
Rm w/ 2 queen beds & private BR ($170)
Rm w/ bunkbed & queen bed ($150)
Rm w/ bunkbed ($120)
50% deposit required
-TLKurtz (Mr. Wizard) - Blackhorse Cavalry Nomads VMG member (2/11 CAV - East/West German Border)
2015 RGS - Vivid Black, Stage I, many extras and much more to come.