Shape - there's a reason it's called "Bodybuilding" and not "Muscle Growing". Exceptions? Sure. But the overall shape is way more important imho.
Shape for certain! Jodi Miller has beautifully shaped biceps, but since she is only 4ft11, she can't compare when it comes to inches to some much bigger women.
shape.... don't get me wrong... size is nice too, but I can appreciate shape more
Some size is important (obviously, in light of the nature of this website), but given that, shape becomes the more significant factor for me.
Big size but no shape = usually not interested
Something close to ideal: Brittany Viola
Shapely combined with beautiful facial looks. Cindy Phillips and Dani Reardon are prime examples of this.
In other words, do you like it when a girl is big or shapely?
I would say shapely is when a girl isn't huge (by schmoe standards), rather she's simply building muscle suitable for her body type.
Big is when a woman is clearly trying to build the most muscle, pushing her physique to crazy limits.