for me its my thighs mostly and i guess my bum, but it follows me and i don't pay too much attention! Also my breasts are big, but other than that I have a reasonable small upper body. (I am an awkward 10G bra cup!)
I find though working out my lower body, my legs don't slim down, they just firm and thicken!
It is interesting how body that weigh the same differ in appearance.