I've read books but I will always will go for Triss.
This! I have read all the books and frankly this was pretty much the only thing I really could not get - why the hell did Geralt get entagled with Yen, who is a cold, manipulative b*tch who obviously got some serious issues with herself (with her background and all - inside she is still the ugly one) and just uses him as she sees fit. In real life, she is the type who would ruin your life. True, there are men in real life, good men, who fall for these types of women. But Geralt? Isn't his life already complicated enough? So, it was actually a nice surprise for me in W1 that Yen is missing, Geralt has amnesia (which means he no longer is under the Last Wish spell, which was imho some kind of self-induced hypnotic suggestion) and has a chance for a new life. Free again and free to reshape his life for the better.
Yen is like the prom queen, the queen b*tch that you fall over and hope for the best, but in fact you get hell on earth instead. Triss is kinda the girl next doors, but she is the real deal. I think that her continuing friendship and concern for Geralt in the books attest to the her genuine love for him, as well as for Yen (who does not deserve this sentiment in the slightest).
So I am glad that Geralt can now genuinely decide who he loves according to each one of us. There are Yen fans, well, cool, their Geralt gets down with Yen again (although that is not something I would wish even on Eredin). There are Triss fans, me including, obviously, and their Geralt gets finally girl who genuinely cares for him. Sure, it would be great if CDPR got romancible Shani back in an Expansion, but I never saw her as anything than a side flirt. She too has a lot of fans, though, and she is ok as a personality as well.
I hope that for EE CDPR will expand the Triss content a bit as it is very underwhelming and after W1 and W2 Triss romance path CDPR seems to nudge players in the direction of Yen in W3. Triss deserves more screen time in W3, for sure.