Well, let's say someone used magic to force you into being in love with them, that verges pretty closely to mind control imo, and justifies anger. Yen could have been angry he didn't wish for something else. Also i don't think that assuming his love for her isn't real, he could've fallen in love before the wish, and wished that she loved him back.
I like this discussion, because I find it quite interesting that I disagree with just about everything you just said (this isn't an attack, I just want to drive the discussion forward).
First of all, you seem to have read the books. But I can't help but notice we have very different interpretations about some things that happened in the books. This is actually one of the reasons people like to argue about this because the books were sometimes so vague or simply left information out on purpose.
First of all, let's talk about the Last Wish. You seem to think Geralt fell in love with Yennefer and wanted her to be in love with him too, so he used the genie's wish to mind control her. When I read that story, that isn't at all how I see it. Geralt doesn't show any signs of being in love with her. He doesn't even like her that much (makes sense considering the in my opinion downright evil actions so took in that story) and comments about being able to see through her magically altered appearance due to his witcher sense. Him later never mentioning this again signals to me that the wish took care of some of the issues he had with her, but that's just my interpretation. The wish also wasn't like 'make Yennefer fall in love with me', the books never even actually say what the wish was. I agree with the games in that it was something like 'let our fates be forever intertwined'. He did this not because he was in love with her, but because it would save her life. Yennefer had pissed off the genie, but the genie couldn't do anything because he was still tied to Geralt until Geralt had made his last wish. He alway knew the genie wouldn't be able to kill his master (Geralt), so the only way to ensure that the genie wouldn't immediately kill Yennefer upon being freed by the last wish, Geralt wish for their fates to be intertwined. Now they genie either had to kill them both or let them both life, thus saving Yennefer's life. I hardly think it's fair to blame Geralt for this and it doesn't give Yennefer any kind of reason to be angry. She was already angry and bitchy before the wish as well.
As for Geralt sleeping around a lot in the books... did I miss something? I only remember a few instances of that happening and they weren't just 'oh, let's fuck' moments. There were usually feelings involved and Yennefer doesn't have any 'exclusive right' to Geralt's affection. Also, that doesn't explain why you don't mind that Yennefer did the exact same thing in the books.
About Triss in the games: Let's be real here... How would she have inquired about his relationship status with Yennefer if Geralt had amnesia? Think about it. That's impossible. As for her sleeping with Geralt without knowing if he was in a relationship with Yennefer... he agree didn't he? Triss didn't know about his amnesia (most likely) during that first night, so she had no reason to assume it would be wrong of her to at least ask Geralt if he wanted to sleep with her. As for not stopping after she knew Geralt had amnesia... they didn't even know if Yennefer was still alive. In my opnion there was no reason for to stop going out with Geralt if Yennefer was in some unknown location, possibly dead. When they learn that she is alive in Witcher 2, Geralt and Triss have been in a relationship for a while. It would make sense for them to continue and not just break up because 'oh, Yen is still alive'. I was kind of pissed to be honest that Yennefer in Wild Hunt seemed to immediately assume they'd get back together and I couldn't tell her 'no way. not gonna happen' immediately.
As for the Yennefer cheating part: That doesn't excuse her actions to me. She was unfaithful and that's all there is to it. Doesn't matter the reason or what you learn from it, it's a shitty thing to do and she should (in my opinon) not just be forgiven for that. The books after that act like it never happened and that didn't sit right with me.
As for Yennefer's mind control: Once again, it being 'sweet' occasionally doesn't excuse it. Geralt constantly tells her to stop it and she doesn't listen because she doesn't give a fuck about his feelings on that matter. Also, actually mind controlling Geralt to murder rather innocent people in Last Wish is also something that gets strangely ignored by Yennefer fans and the books. That's evil, no way around it.
As for Yennefer's dislike of Kaer Morhen: True, it's kind of a dump. But it's her boyfriend's dump. And Triss is perfectly okay with it and even kind of likes it there (despite Lambert not liking her). And doesn't it say something about her that the other witcher don't like her? They have very good reason to dislike her. I'm not sure, but I also remember her saying things like 'you're just a witcher' in Shard of Ice and she always seems to think being a sorceress makes you awesome and better than a witcher.
About Triss doing nothing wrong & The Kiss at Kaer Morhen: 'Marking her teriorty' is just a shitty thing to do. Is that really an excuse? Jealous and not knowing your boundries is what it is. It also shows disrespect for Geralt's decision to go with Triss and it shows disrespect to Triss herself, who she is supposed to be the best friend of.
I also don't agree with Triss 'stealing' Geralt from Yennefer. She didn't think 'oh, let me grab this opportunity to screw over my best friend now that Geralt has lost his memories'. She was already in love with him during the books and to me it makes perfect sense for her to go after Geralt when Yennefer is out of the picture. Once again, Yennefer has no exclusive right to Geralt. And unlike with Yennefer, to me it feels like his love for Triss is real. This is just how I think it happened (my sort of head-canon I suppose): The amnesia given to Geralt by the Wild Hunt negated the effect of the wish due to him not remembering Yennefer. This meant that his feelings for Triss could grow more naturally instead of them being forced by magic (to me it was clear Triss and Geralt already had feelings for each other in the books, but they didn't act on them because of Yennefer). So we have forced love for Yennefer vs actual, naturally grown love for Triss. There can only be one winner for me, I'm afraid.
As for the scene in the Freya's Garden (was it Freya? I can't remember). To me it's very interesting that you see this as a possitive moment for Yennefer. Because that very scene is my most hated scene in the entire game and I can't get through it without reigniting my dislike of Yennefer. It shows that she has no respect for anyone (not the dead an not Geralt), she doesn't care that Geralt is against the ritual, she doesn't really care she destroyed a divine garden in the process, she doesn't care about seeing the dead guy in obivous pain, etc. I could go on and on about this scene. Sure, she might care about Ciri due to a somewhat dangerous obsession with having children of her own in the early parts of the books, she just doesn't know whet she's going too far. The ends don't justify the means, so to say.
Anyway, I'd like to know your thought on this. I doubt we'd ever agree, but that's okay. It's just an interesting discussion topic.