"Be not afraid of greatness," the Bard tells us. "Some are born great, some achieve greatness, and some have greatness thrust upon 'em." It's a maxim as true in professional wrestling as it was on Shakespeare's stage. Not everyone gets to be the main attraction, though.Sung or unsung, the wrestlers on this list had just as much charisma and in-ring ability as their more well-known counterparts, and often put many main eventers to shame. Some were held back by the tastes of fans and promoters. Others caved to their own excesses. All played a critical role in making wrestling the modern spectacle it is today.