>>3274637n and e-hentai. The Digital Lover ones are 90% her saying "No" over and over again and Kyosuke doing it anyway. They're drawn well and good otherwise, but that's hardly a Kyosuke thing to do. And while she does eventually say "yes" by the end of it, her continual "No's" don't really sit well with me. Even if "it's only rape if she says 'no' and doesn't like it," Kuroneko deserves more care than that.
As for the threesomes...some are good, but a lot of them involve it either being a "competition" between the two or it's Kuroneko being extra lewd and practically dragging Kirino into the bedroom before stripping her clothes off.
Clearly I'm looking at the wrong ones, so feel free to toss out some suggestions.