It really depends on what I'm wearing.
Bare legs seem to be more in fashion than suntan hose these days. Of course it's nice to have something on your legs in the winter. But unless my outfit really calls for it, I try stick to gray or black tights as they are heavier than hose and you can get a couple wears out of them without a run. I don't care for garter belts or elastic top thigh highs, but a big plus of stockings is if you rip one, you haven't ruined the whole thing like pantyhose.
Leggins are usually even heavier and the lined ones are great in the winter. They hold up a ton better than tights or hose and they come in all kinds of fun prints. You can dress them up with a nice top, but leggins tend to be more casual. The bare ankle look isn't my thing so unless I am coming or going to yoga, I usually wear leggins with socks and boots. It's still sort of a fashion no-no for people to be able to see the top of your butt, so most of the time I wear skinny jeans or jeggins so I don't have to be so careful when I bend over or sit.