I'll be honest, I haven't read the comic books. It's been a while since I kept up with any ongoing series or even been into a comic shop. Most of my comic book consumption comes in the form of movies and games now days. A lot of times this can have a detrimental effect on the movies. If you know the history of a character or franchise, it really sucks to see Hollywood take it and package it for the masses. X-Men and Spider-Man started really strong, but ultimately nose-dived into shit territory with the third installment of each. At least we're about to get another awesome Iron Man movie, not to mention Captain America and then the Avengers.
Anyway, Kick-Ass really felt like a love letter to comic books. Anybody who's ever read a comic could identify with Kick-Ass. He was like-able and it really hurt when he got hurt. The real star was Hit-Girl. She's the one with the tragic back story and reason for revenge. You even get a little misty at a couple parts because she's so young and so alone.
I hear the story was changed from the comic book, and normally that would bug me, but since I never read the funny book, I don't have that connection with it. I kind of wish I could remove myself from other characters and just enjoy them for what they are up on the screen, but it's so hard to watch Deadpool extrude swords from his arms, shoot optic blasts, and teleport. It may look cool, but when does it stop being an homage to the character and just become name lifting?
I'm worried that Whiplash is going to suffer from this syndrome in Iron Man 2. Cherry picking the parts they want to use from different villains to make a story work. And you may argue that sticking too close to canon leaves us with movies like Daredevil or Ghost Rider. And I'll tell you, those movies are much more enjoyable than X-Men 3.
And I'll tell you one thing right now. Seeing Elektra killed on screen almost exactly like the comic book is still a memory that stands out for me.