I'd have to say a combination of the first 2 but of course there has to be part of the third as well, imho.

I've fallen in love with others that didn't love me, so that of course is possible but I can't be with someone that doesn't love me as well and vise versa, I can't be with someone that loves me while I don't love them.

I'm fortunate enough to have found someone that fits all three listed types. I am madly in love with him and the way he makes me feel about myself and I know he is madly in love with me and I how make him feel. He has wonderful characteristics that heavily out weight the few flaws he does have. In my opinion, I feel in my heart is the one for me and is my soul-mate.

These are just my personal opinions, of course. I know there are many that disagree about love and such which is perfectly acceptable.