The sloppier, the better. Lots of spit and gagging. When she is holding back tears, gagging herself for your pleasure and then pulls off my cock with the spit hanging from her mouth to it. It is so super sexy.
Aside from that, I really love it when women go deep on the cock, and then managed to swirl their tongue on the head meanwhile. That shit is great. It goes without mentioning, I suppose, that sucking (not licking) balls is also great for likely every man ;-P