I like the first one the best. It has a clean background, decent lighting, and there's a certain "classy" androgyny given to the subject because of the clothes and the cigar.
The one I like least is the last, because shooting homeless people in the simple context of "homeless = interesting" is low hanging fruit, but also because it seems disorganized. I can't see the relevance of the sign as either a metaphorical symbol or a literal object of visual interest. After being inundated with images of the homeless, it's become cliche.
The second is a little more interesting. I like the juxtaposition of the two casually dressed people walking next to the bundled up guy slumped over.