RK. Best "porn" feel i get from a paysite. Their banners and stills are amazing, really gets your juices flowing. What i don't like is their member area navigation.
Brazzer is ok, but looks too much like all other paysites in same category, and their images are just that, images. When i see an RK image, i really think, "wow, that is one banging porn scene" (which is not always the case
).