I've heard a lot of noise made about how Deadpool's R-rating contributed to its success, and how it might open the floodgates for more R-rated action flicks. While I'd agree that the potty language, ultraviolence and lashings of the old in-out appealed, I think there's more at play.
In Deadpool, the city/planet/galaxy/universe isn't at stake. The stakes were personal. That's pretty rare in comic flicks these days. Even in Dredd, although the city/planet/galaxy/universe wasn't at stake, neither Dredd nor Anderson really had a personal link to the events that unfolded around them. It was just about their survival. Neither had any personal greivances against Mama, she was just another perp, whereas Wade had clear personal
motivations in going after Francis
. Even though Deadpool's protagonist was an unrepentant murderer, who utterly rejected any ideals concerning heroism and had a face like a prune with herpes, the movie did an excellent job in gettting me to root for him.