The bad guy who deep down has a heart and turns to good – or at least partially good. It is a classic screen trope and one we just can't resist. So it is little wonder that Suicide Squad, the DC comic caper about a bunch of dangerous supervillains brought together to fight an even bigger and badder villain, has been one of the most anticipated films of the year.

Here, we look at the top 10 screen bad-guys-turned-good to have left an gnarled fisted-sized impression in our minds.

Harley Quinn

I wonder, who could possibly ever go as mad as the Joker? His psychiatrist of course. Originally Harleen Frances Quinzel, a psychiatrist at Arkham Asylam mental institution, she went totally insane after having the Joker as her patient and fell madly in love with him. In the upcoming film Suicide Squad she is one of the bad guys, being forced to do "hero work" for the government against her will. Or is it against her will? Maybe she thinks it’s fun to play the hero. She’s too insane to be able to tell the difference.

Darth Vader

The most iconic villain in all of cinema, Darth Vader has the lowest Good:Bad ratio on this list. After three films of darkness and destruction (and asthma), he is eventually the one who saves the day at the end of Return of the Jedi. After losing a duel to his son Luke who refuses to turn to the dark side, Darth Sidious electrocutes Luke with the intention of frying him to a crisp. Seeing his son in pain and the dark side for what it is, he picks up the Emperor and throws him down a hole to his death (and is silent as he does it, he doesn’t say anything). His sacrifice saved the galaxy from the dark side, until Epsiode VII …

The Punisher/ Frank Castle

Most recently seen on season 2 of Daredevil on Netflix (we shan’t mention the 2004 film abomination), Frank Castle, aka the Punisher, is the archetypal anti-hero. To the dismay and horror of goody-two-shoes heroes such as Daredevil and Spider-Man, The Punisher chooses a much more final solution to removing criminal scum from the streets. Once a meticulously trained US marine, Castle took his skills and began to kill effectively and without mercy the worst of the world’s wrongdoers.

Dexter Morgan

Dexter Morgan, as seen on the popular TV show that bears his name, is a serial killer that is driven by his obsession with blood, born out of a scarring incident from his childhood. How can this psychopath be considered as doing good? Well, he only goes after the worst of the worst, so you could say he’s doing the world a favour. He also tries to raise a family and lead a normal life, but as you can imagine this doesn’t necessarily work out so well for him.

The Terminator

The infamous Terminator is a hard one to pin down, as each film stars a different version of the Austrian robot. As seen in the first Terminator, this robot was designed to find and kill Sarah Connor to prevent her son John from leading the resistance against the robot takeover. However the resistance captures one of these terminators and reprograms it to protect John Connor. A destructive robot redesigned to protect through no will of its own? It still counts.

Gru

Felonious Gru, once the world’s greatest villain with the world’s most ambiguous Eastern European accent, tries to steal the moon in Despicable Me in order to come back on top. However upon adopting three orphaned children, he grows a soft spot for them and gives up a life of crime to become a father. Also he saves the world from two super villains and has an army of contagiously adorable minions, how much more good can he do?

Captain Jack sparrow

The role that Johnny Depp can never escape. Captain Jack Sparrow is a proud pirate to the core, and while he does like a good plunder or pillage of a defenceless town, in every film he does the right thing in the end. Whether that’s preventing Will Turner from being sacrificed to remove an Aztec curse, or return to his sinking ship to save his crew form the Kraken. He may have become more hero than anti-hero in recent films, but a pirate’s a pirate. Savvy?

Deadpool

The "Merc with a Mouth" has exploded into popular culture in recent years with his hit R-rated film back in February. Wade Wilson has no qualms about chopping and shooting through bad guys like Zack Snyder through a film script. The high body count in his film and the abundance of gore shows that he ain’t no good guy. But he does it for love and steers clear of killing good guys (at least for now). And what other comic book character provides his audience with charming fourth-wall breaking humour?

Jaime Lannister

(Beware... spoilers) The Prince charming of the Game of Thrones world is a slippery one. As soon as you feel like he’s turned over a new leaf and become a do-gooder, he flips that on its head and does some messed up stuff. He may have killed Ned Stark’s body guard and crippled Ned himself, sent his regards to Rob Stark and done naughty things with Cersei over their son’s dead body. But he’s also saved his brother from execution and saved a woman he fancies from a bear. A mixed bag to be sure.

Magneto

An all-time comic books and film favourite, Magneto has a fantastically complex character, especially coming out of the most recent X-Men films. While in the first three films we see Magneto simply as the antagonist fighting to destroy humanity, in the more recent films we see him working with the X-Men to prevent the creation of the genocidal Sentinals, and turn against the one controlling him in X-Men: Apocalypse. And he does what he believes is right, to protect his own kind. But throw in magnetic superpowers and persecution as a child and you get a pretty messed up psychopath.

V

V for Vendetta, a very underrated film, is set in a dystopian future where America become desolate and diseased, and a right-wing authoritarian government has taken over Britain with discrimination, extermination and experimentation of groups of people. The Nazis 2.0 basically. A terrorist or freedom fighter, going simply by the name V and wearing a Guy Fawkes mask, fights against this government and dismantles it through arson and assassinations. Depending on which side you align yourself with, he’s either the hero with questionable methods, or just a villain.