I'm with Dan on
A Serbian Film - it's comedy, for me, I'd even go as far to say it's an outright comedy from beginning to end. The characters are incredibly over the top and the gross out scenes, whilst not from the Farrelly Brothers stable, they're not far off in that everything appears to be purposefully fake, unlike say
Kill List which attempts realism to genuinely shock.
I showed
Martyrs to my wife and it pretty much stopped her from watching any films that I choose now. She found it genuinely disturbing and had nightmares for a long time afterwards too! I guess she was mildly traumatised by it if you want to get medical.
Ever since though I've been trying hard to get her to watch
Inside, but she'll never ever watch it unless I tape her to a chair with those eye-opening devices like Alex in
A Clockwork Orange.
I think the whole mother/child bond is something that blokes will never really understand and without wanting to generalise, it's much more common I believe for a woman to be really swept up and emotionally involved in a film, certainly for me there's a little switch that flicks on when I watch anything remotely 'horror' and I just process the movie as fun (as much as possible) and 'not real', but that's just me.
My wife and I saw
Enter The Void at the flicks in France and she was extremely upset ie. she was crying and gripping my arm like a vice during the rather graphic abortion scene - a scene that was powerful, but didn't bother me in any way at all.
As an addendum, the first film my wife and I ever watched together was
Irreversible 
- so maybe the damage was done way back then?!
But actually she loved
Drive -then again that stomping scene was so heavily cut that it's more about what you hear and I guess it's a tragic love story that appeals to her girlie sensibilities
