I just finished reading A History of Violence. I was extremely impressed with the movie last year, and had heard that the comic was even better, so had high expectations.
Unfortunately, I was rather disappointed. While it was a rollicking good romp and a good fun story, it seemed to have lost most of the thematic and character complexity and subtlety that was in the movie. Which is odd, considering how much larger the story is in the comic.
It felt a little like the movie had taken some of the core themes and ideas briefly touched upon in the comic and really explored them in depth, while jettisoning a huge part of the story itself. The comic, meanwhile, has a lot more story but, for me, a lot less interest.
Beware: spoilers below for both the comic and the movie!
For example...the interaction between Tom and Edie. In the movie, I found their reactions extremely believable, from the natural portrayal of sex to Edie's horrified and conflicted reaction to events as they unfold. The horror and uncertainty she goes through is brilliant. In the comic, as soon as she's learnt what's going on she says "That's ok, I love you." All too easy, if you ask me.
Similarly, I found Tom's eagerness to divulge his story to anybody that wandered past a little strange. His desperate attempts to retain the facade in the movie seemed more compelling and convincing - I can't see him giving up 20 years of fabrication so easily.
Bottom line, I suppose, is that the characters in the movie are very different to the characters in the comic. Personally, I found the movie characters more interesting and multi-layered, whereas the comic characters seemed there only to serve the story.
On the other hand, the Richie story was far more interesting in the comic. The bizarrely comic Richie elements in the movie never did quite sit right with me (though I need to watch it a second time to make a proper judgement). Richie's 20 years of hell in the comic is a very powerful and horrifying concept. Certainly more interesting than a whiney brother who has never quite attained his 'rightful' place in mob society.
Don't get me wrong, though - I still thoroughly enjoyed the comic. I just felt it lacked the depth that I was expecting.
p.s. Just read your review of the movie, Kater. Excellent review, though I come down on the positive side of the fence a bit more than you. But I've always had a soft spot for Cronenberg's deliberately slow pacing.