I stopped watch the show in season 2 at one point for 'this is disgusting' style reasons. Then I picked it backed up at the start of season 4 (i watched the stuff I'd missed, too). Last season with the Jamie/Cersei rape scene - wait was that last season uhhh - I was ready to quit it again but then I think the season ended and I forgot about that by the time this one started.
Now the show has depressed, annoyed and disgusted me again.
Y'know, it isn't just the showing of rape. I don't have an inherent problem with that being used or shown as part of a story - although I can't think of many reasons to be excited about watching that kind of thing, unless it was a major theme - it's the way this show does it. It's pointless. Maybe you could make a case for it being shown a couple of times, or referred to as happening, but it's the way the show seems to just revel in itself.
I mean they used this to end an episode. It's the last thing you see, poor wee Sansa getting the shit kicked out of her again. And we don't even on Sansa, we end on Theon!
It's just a pointlessly disgusting show some times, and not in a good or fun or fascinating way. In a dull, repetitive, poorly thought out way that enriches pretty much nothing about the story.
What did it add? Fuck all.