My favorite is being on my forearms and knees and being mounted from behind, but cowgirl is right up there! I like how my breasts jiggle in front of him and are so available for him to squeeze and twist and pull on.
My breasts aren't large, 32B, sorry guys. I know that most men like big boobs, but I am just not built that way and am comfortable with how I look. It does help me role play young, which is easy for me to do.