I'd probably go with the classics, either headscissors or (obviously) the facepin/sit... Although I see the latter as more of a victory pose, rather than something to use IN a fight. The facesit is more about the final act of domination for the winner and humiliation for the loser.
Of course, the headscissors can provide that same 'double whammy' when the aggressor applies a crotch-to-face headscissors... which is, essentially, the best of both worlds!
