4) Keanu Reeves (Plastic Man)
And now, for one of the strangest superhero movies that never happened. Back in the 1990s, a film based on obscure DC hero Plastic Man was in the works. And none other than future Matrix directors, the Wachowski siblings, were behind it. After making their sci-fi magnum opus, the pair restarted the project and even courted a leading man. Bizarrely, they wanted Neo himself, Keanu Reeves.
The mooted movie was floating around until as late as 2008, where its future apparently depended on the reception to The Dark Knight. After that movie was a massive success, Plastic Man was one of many DC films to be cancelled – along with Batman vs. Superman (the first version) and Justice League Mortal. And so, alas, we never got to see the stony-faced Reeves attempt to play an out-and-out comedic character like Plastic Man.