Hmm, I think the hardest kink for me is forced pleasure/forced orgasm. For me it doesn't matter if I play the top or the bottom, I just love it when the bottom characters can't escape pleasure and the resulting orgasm, no matter how much they protest, fight, try to resist or beg. XD
My weirdest kink... that's harder to decide. I had to think about it for a while, lol. I think my "old" weirdest kink was when MC's neck and back get a lot of attention. Those are my favorite parts of the body. Probably not weird for most people, but unless I play against a Vampire it's hard to find people who give those parts more attention than a brief kiss or stroke.
Recently though, I stumbled across a video of two trans people fucking. One was ftm, the other was mtf. So basically it was a straight sex video, but their genitals were reversed. That kinda stuck with me and is apparently on its way to become my "new" weirdest kink. However, I'm less interested in realistic trans people there, but rather the fantasy-like versions, i.e. born shemales and c-boys, if you know what I mean.