Which sister, aged based, would you prefer?

[color=red]Already have imouto and I believe my twin will be as ugly as me so, onee-chan.
Besides I can't see my twin/imouto in a romantic way and... I prefer older girls >_>

Onee-chan=Big tits in my dictionary.

A smoking hot twin sister wouldn't be so bad though

well, I would't refuse any of them exept they are too young [I'm not a loli fan though]
but I prefer Onee-sans <3

I don't understand twincest - look too alike.
It was quite choice between Oneesan and Imouto though. Though loli and kawii is good, being pampered wins out

Older, though a threesome with both, or a foursome with the twin XD would also qualify.

The Onee-san. It feels good to be the younger partner, to be led and to give up control.

Onee-san, an Onee-san who will spoil me in various ways that is.

Having an Imouto is not that bad though. But what if you're much anticipated little sister turns out to be a brat:(

Imouto is def the best

i'd choose twin as long as it was opposite gender.