I dunno about 'cool', but the ladies win hands down when it comes to sexy avatars! When it's an avatar of themselves that is. (And they know exactly what effect their avatars have on us boyos!!)
My vote goes to Emmasweet's previous avatar - the one which she had a lone ranger mask on! Sexy or what, phew!!!
Although her current avatar showing off her sexy ass, is pretty damn cool too!!