There have been many hunts over the past 15 years that have somehow required or produced duplicate Sams, Deans, Castiels or Bobbys. Occasionally, Team Free Will needed their clones as additional hands-on-deck, but most of the time their duplicates were thrust upon them, and mayhem ensued. Acting opposite yourself is daunting, but the talent of the Supernatural cast has always been up to the challenge, with memorable results! Let's take a look at Supernatural's mirror universe!
1.06 "Skin" - Dean vs. Shapeshifter Dean
Only six episodes into the series, Dean is cloned by a shapeshifter, who commits terrible crimes while impersonating Dean. Reflecting the bizarre reality Dean lives and works in, he hunts himself down. The clone is killed and Dean escapes capture but Dean is now a wanted man. 
5. 04 "The End" - Dean vs. Croatoan Dean
When present day Dean is transported to the future, he meets Croatoan world Dean. It is not a pleasant reunion! Dean learns that if he continues to push away his brother, in just a few years Dean will turn into a bitter, cold hunter, hardened by all the betrayal, failure and death that he endures.
5.22 "Swan Song" - Sam vs. Lucifer Sam
After Lucifer possesses Sam, we hear and see the internal dialog between the powerful archangel and his defiant vessel. All is revealed to Sam in this debate - answers to questions he has asked his whole life about why he has been cursed with an endless string of deaths and heartaches. The camera work and direction with the mirror that portrayed Sam's internal battle is gripping.
6.22 "The Man Who Knew Too Much" - Sam vs. His Memories
In a chilling climax to Sam's year of having either no soul or only a splinter of a soul, Sam's mind battles with itself as the memories of Hell and being a soulless hunter break through into his reality. The story, and the acting, are brilliant.
7.06 "Slash Fiction" - Sam, Dean and Bobby vs. Leviathan Doubles
Leviathan Sam and Dean go on a public crime spree with the specific intention of getting the real Sam and Dean arrested. Meanwhile, Bobby interrogates a leviathan goon they captured, and experiments with ways to kill the prehistoric monster. Thinking he'll mess with Bobby's mind, the prisoner takes on Bobby's shape. In the end, our hunter heroes outsmart and defeat all their leviathan doubles. 
13.04 "The Big Empty" - Castiel vs. The Empty Entity Castiel
After Jack grieves Castiel's death so fiercely that he wakes Castiel from his eternal slumber, Cas is confronted by the keeper of The Empty, the realm where angels go after they die. The Empty takes on Castiel's form to taunt and torture him, hoping Cas will go back to sleep in defeat. Cas, however, defies the entity, eventually achieving resurrection and a one-way ticket back to life on Earth. 
15.13 "Destiny's Child" - Sam and Dean Team with Hunter Corp Sam and Dean
In a rare comedic cloning encounter, the bunker is infiltrated by a Sam and Dean from another universe. These brothers are refined and mellow, having lived a life of luxury after their father incorporated and commercialized the business of hunting monsters. They agree to double as our world's Sam and Dean to fool Chuck, then they remain in Sam and Dean's universe, hopefully to resurface sometime in the future! 
Update: I challenged the WFBFamily to find more Double Trouble episodes that I missed and they did it! With the following additions, we can officially call this a TOP 10 List!
#8 "Bloody Mary" 1.05 (added by Marion) - Sam vs. Guilty Conscience/Bloody Mary Sam
#9 "Dream a Little Dream of Me" 3.10 (added by 'Waiting for Aslan') - Dean vs. Guilty Conscience/Unforgiving Dean
#10 "There's No Place Like Home" 10.11 (added by Marion) - Dark Charlie and Good Charlie
#11 13.22 "Exodus" (added by Annabelle Lee Williams; gif found by Chery42) - AU Nazi Cas vs Castiel
#12 "Gods and Monsters" 14.02 (suggested by Reet Gupta; found by Marion) - Michael Dean vs. Dean
Did I miss any double trouble episodes? If so, please add them in the comments! Do you like when Supernatural gives the actors multiple roles in one show? Which were your favorites? Who else would you like to see cloned? Comment below!
Enjoy more of Nightsky's reviews of Supernatural! You can find all her articles on her writer's page.
