Rib Shack in Eagle is very good, heck they will give you a rib to eat as you standing in line looking (or used to, been a couple years). go with the burnt end dinner with cheesy potatoes.
I think they have a second location in downtown Boise, but not sure anymore.
EDIT:
I'll call my brother, he live's in Boise area, and ask about the second location, and make sure it's open