I'm fine with both. But if I had to choose I prefer regular girls. I used to like fantasy settings very much, but nowadays it takes away some of the weight of the fetishes I'm into.
Depends on the monster level. If it dont has a human pussy shape its too much for my taste. For example, there are 2 types of spider girls, the acceptable ones have a human pussy on the human front, the others have a cloaca on the spider back.
If its far from a human form it also dont offers any appeal for me.
So nekos, vampires, fairies, demons and whatever are very welcome, but stuff you cant really call female or humanoid isnt my thing.
mostly regular, but if a game has alot of regular girls and maybe 1 monster girl, then I actually like that because it throws some variety into the mix.