I've been testing the gaming offer that I'm running on ppv with facebook traffic as well lately.
I launched 30 ads with different images same ad copy. Ages 17-23 males who like harry potter, hobbit, lord rings, lotr, star trek, star wars, star wars clone wars, star wars knights old republic or star wars old republic.
Images used:

The best ones only received .08 ctr. Just wondering what would be used in this case? I found those on deviantart, worth1000, google images. Figured with all the colors and scifi that they would get a high CTR but this wasn't the case.
Offer is for a MMORPG. Should I choose different images or different keywords?
Even though there nice images, there's 2 key points your missing when trying to attain high CTR
1. The images don't really relate to what your targeting, there not irrelevant but there not spot on either
2. None of them make you go WTF, or WOW!
See that's what I was thinking is there isn't really a wtf factor in them. I just don't know how to go about linking the target with the offer from the picture though.
For example using the target lord of the rings, trying to find a wtf picture that is relative to both the target and the offer seems impossible. Since I'm direct linking that would mean I have to do all the relating in the adcopy or image.
I know what your saying, but it's unlikely these images will yield a better CR than a lord of the rings 'wtf' image.
Generally for gaming/iq traffic you want to focus on getting as many clicks as possible for super cheap! I say try some wtf images and see how your CR differes, i think in the end your ROI will be up.