Len Riggio must be kicking himself. The chairman — and largest shareholder — of Barnes & Noble (NYSE: BKS) rebuffed a takeover last summer from Ron Burkle of Yucaipa Investments for a reported $20 a share. At the time, I thought any buyer of the beleaguered bookseller would simply inherit a bunch . . . → Read More: Now’s the Time to Buy this Comeback Stock