I'm not looking for your "my woman/my man is perfect, I would want someone just like him/her". If you could choose exactly one thing your significant other had/did, what would be the one thing be? And I don't just mean a "cute butt". Go into a little more detail.

For me (a perfect thing, not specifically THE perfect thing) would be the breasts. They can't be too big. But not too small. That perfect in-between of a B/C but with a certain amount of firmness and lift (naturally) that it makes you drool at the thought of it.