What is the most gratifying sexual act between two female bodied people?

My absolute favorite involved the Share (by Fun Factory). With the short end inside of myself, my girlfriend gives the other end a blow job. The visual is incredible and the motion of her mouth and hands moves the share just enough to stimulate my g-spot. It gives me the wonderful feeling of being dominant and as soon as I orgasm, she's able to hop right up and ride me. (=

There's nothing better...

Tough question! I think I'll have to go with her finger fucking me while she sucks on and teases my clit with her tongue.

Finger fucking WOOT!

I find it very hot when I see my girl orgasm because of all the things I am doing to her.

Watching from a guys perspective.

It really depends greatly on my mood. Oral sex is a favorite, especially with fingers inside. Fisting is incredibly intimate and amazing. Strap on sex is brilliant. I don't know if there is any one single most gratifying act.