It looks good when the "thickness" comes from muscle tone/muscle mass and not fat. Your legs should be firm regardless of the size. So slim and toned or thick and muscular (bot at the same time not manly) is ideal.
Guys have liked women since the dawn of time, Its in our biological makeup. Preferences are nothing new, thick thighs, medium thighs, skinny thighs, who the feck cares femininity is femininity. Guys are attracted to women plain and simple.
i read about this in biology...men like women to be fertile looking who will have healthy babies and carry a pregnancy well and having thicker legs with hips to waist ratio means she's healthy to have a baby and will carry it well for 9 months
it makes sense because its hard to imagine a skinny chicken legged grl carry a baby...she won't be balanced nor proportionate and will be weak throughout the pregnancy with backpain and muscle aches whereas a woman with healthy hips and thick legs will have muscles and strength to support her and keep the baby safe