Eh, my requirement is your attitude/personality. The answer to your question is yes, I do need to talk to you first. Looks are bonuses for me

Definitely need to get to know you first.
BUT, I think I can usually tell just from observing a person w/o talking to them how much I may like or dislike them.

I personally think that love at first sight is simply lust at first sight, since love is a chemical reaction that accompanies affection and attachment. Surely you are not attached to someone merely by how they look, nor do you have any strong feelings for them.

Not a female, but I think I do fall in love at first sight. I mean, when I see a girl I really like and start thinking about her, I tend to idealise her and start imagining she has this superior personality. I'm like, in love with every aspect of them even though I don't even know most of their aspects. :/ It's pretty painful actually.

I've only experienced love at first sight with puppies.

I met my husband online and we chatted, had video chats, IM's (this was in 98 - 99). Soon I knew I liked him. After a while I knew he was the one. We met after a year and a half of chatting and I fell for him toward the end of a two week visit. So I guess I knew I wanted it to go a certain way (he did too), but there was no love at first sight.