A girl that is ok with going for multiple rounds is a really great thing, and as far as I'm concerned a minimum requirement. A girl that will make it her mission to keep you going and get the next round off, now that is something special.
A looooooooong time ago when I was young and stupid and had no clue what I was doing or even capable of doing, I was with this girl and we had a really nice round with a lovely finish. She hops up and says to me "that was fun, I wanna do it again" and skips off to the bathroom. I didn't think she was actually serious, or at least certainly not right away, but she comes back from the bathroom, dives under the covers and proceeds to get me going again. Ever since then I've been obsessed with insatiable women and when shopping providers always look for the msog availability.