In order to survive in the long term, Comic Book films need to evolve and stop becoming cliche. I disagree that they are over saturating the market but I think a point can be made that new and fresh stories need to be told. Deadpool is that film. It is absolutely a game changer and a breath of fresh air for the Comic Book genre.
What made "Deadpool" work was it's Comedy. This is flat out one of the funniest movies I have ever seen. 99% of the jokes work. Most of the credit is due to Ryan Reynolds. He is absolutely perfect as Wade Wilson/Deadpool. It's very rare that while watching the film you don't see the actor but you see the character they are portraying. Ryan Reynolds IS Deadpool in my mind. The supporting cast also did a marvelous job with the Comedy. T.J Miller and Morena Baccarin stood out in my opinion. They both worked really well with Ryan and had great chemistry. I really believed the relationships they had. Speaking of relationships, Reynolds's and Baccarin's worked. This film worked because you believed their relationship and it made all the action, jokes, and trials worth it! You wanted them to succeed and thrive. The villain of this film, Ajex, played by Ed Skrein, worked well for this film. He was exactly the Villain that Deadpool needed. Ajex isn't this deep, brooding Villain, but he didn't need to be.
Summing up, I have no negatives for this film other than very few of the jokes didn't work. Deadpool is arguably the greatest Marvel film in this century, and the funniest one. It's the real deal. Give it your money, and go see it.