I like this one but on the bed. Get excellent penetration this way and it's easier to rub the clitoris. The hip is right there as a handle so you can really pull yourself into her as well. You can smack that ass or reach down and play with the nipples. It really is all access.
As for trying unusual positions. It's tough when you're a tall guy and the girls are shorter. It's even worse when you have a shorter than average penis as there's not much more deflating than getting into some odd position and not being able to reach.
The butter churn looks interesting but I don't bend down that way easily and it would be painful.
Anywho....that's my .02$
