There are a few plot devices that crop up time after time in our favourite TV shows, including the shock killing of a favourite character, the flashback and the 'it was all a dream!' twist. They throw one TV trope after another at us, but there is always one twist that draws in a crowd the addition of an evil twin. Evil twins are intrinsically fascinating an evil reflection of our favourite characters, who usually look just like them but often have decidedly more sinister motives. When the chips are down and the writers are scratching their heads for plot ideas, they'll often throw one into the mix. They're an easy win - evil twins can easily played by the same actor as the good twin, except with a slight visible variation, a distinguishing marker of their evilness like, say, a beard (a sure sign of evil) or a bit of a scowl. To celebrate all of those lazy liars, and also the fact that being so unimaginative can actually lead to good moments, we've compiled a list of the most memorable evil twins in TV history, including a number of notable variants along the way, such as the 'brother-from-another-mother', parallel universe versions of our favourite characters and a pair of twins who are just plain evil. Naturally, there are spoilers ahead...
18. Buffy The Vampire SlayerAfter all that attention Buffy wallowed in throughout the first two seasons, season three pushed faithful sidekicks Willow and Xander into the limelight, and in a brilliant move, both got their very own kinky vampire twinsy selves to mix it up a little. After Cordelia hastily wishes that Buffy had never come to Sunnydale, Anya (the veiny and slightly limp looking vengeance demon) grants her wish in a move that in no way ripped of Charles Dickens or It's A Wonderful Life. Naturally as a result, Sunnydale is plunged into an even more hell-ridden version of itself, overrun with leather-clad goth-vampires led by the Master. What's memorable about Vampire Willow particularly is that she acts a stark reminder of what could have been, had Buffy not been around. Additionally, the character traits Vampire Willow displays arguably foreshadow some character developments Willow undergoes later on in the series. Vampire Willow was so popular with fans that she makes another appearance in the episode 'Doppelgangland', which was apparently one of Alyson Hannigan's (Willow) favourite episodes to shoot. Vampire Willow also wins points for being able to establish a memorable catchphrase in a single episode...'Bored now.'
17. BonanzaFor some really old school evil twins, you have to look as far back as Bonanza, the popular 1960's Western series, and in fact, this show spawned the whole 'evil twins' concept for the first time on TV. The series ran from 1959 1973, and was highly influential but perhaps its greatest legacy was the birth of the 'evil twin' paradox. Little Joe's evil twin in the episode 'Alias Joe Cartwright' is memorable for being one of the first evil twins on popular TV. In the episode, an escaped prisoner who inexplicably look just like Little Joe Cartwright uses the old 'switcheroo' to cause mayhem. Unlike lots of shows later on this list, Bonanza as a Western doesn't fall into the 'fantasy' genre that usually lends itself nicely to the introduction of an evil twin.