The Condemned-copy? And Others

Is it just me or does a theme of random (or innocent in other cases) people are fighting to the death? Do Battle Royale and Surviving the game come to mind? Also The Running Man and the video game Manhunt. I also think that this film is most similar to the film Series 7: The Contenders.
I was thinking that it would be interesting to discuss movies that seem to be copies of each other, or completely unoriginal movies.

Like Blade Runner, Minority Report, Paycheck, The Island, Code 46 and Children of Men? All these movies take place in the 'near future' and/or deal with clones and whatever, but they are all decent movies. I think movies can be similar yet still stand alone depending on the angle of the story. Everything has been done, it's how you do it that matters.