I can't find the image, but my favourite poster/image ever would probably be the girl on the right below in that image but showing a lot more of the image with it not darkened out, like I saw spread over a magazine once. I've masturbated to it so many times it's ridiculous. Often I would be masturbating to something/someone else, but think of this image to do it really well. I'm not sure just what about this image it is, I love it how she is looking back at you, her ass of course, I think the fact that she's a "fighter" helps a lot as well. It helped as well that there were lots of other incredibly hot images of girls fighting in the magazine article (and for the game) as well.
The other cover's not bad either.