4. Ryan Reynolds still squeezes life out of the character
An unpopular opinion: Reynolds is a great performer who just can't catch a break. See Mississippi Grind, see The Voices, see Just Friends, see Adventureland, see Smokin' Aces, hell, see Van Wilder. The guy can act. And, despite Deadpool parading vulgarities like they're circus elephants, he brings a ton of compassion and manic energy to Wade Wilson, the man behind the mask.
In a short stretch of movie, we see Wade fall hard for Morena Baccarin's Vanessa, discover that he has terminal cancer, and then watch Stock British Guy ruin his life with a mutation-provoking treatment. When Deadpool jumps into action, he's a one-trick pony. Reynolds is the real hero, bringing more pizzazz to the role than any of Marvel's current leading men.