It's difficult to determine which one I like best since the contrast on all of them changes with my Ultrasharp LCD monitor tilted at different positions. So I won't go into that (although I believe I like the first one best).
Constructive criticism:
I'm not a fan of the font. It's upbeat and hip, but almost mimicking that of Apple (same font as they use on their site?),. It also suggests a Google-like generic Spartan interface, which people may not want for their Web design. As you well know, the business card often reflects the company attitude and/or production. Is this what he wants to project? Personally I'd change the font to something modern and sans-serif but with a little more pizazz - like Eras Medium ITC or even something outlandish like Papyrus.
Also, I don't feel the name stands out enough. Traditionally business cards have a name in bold or some detail, of course. This you accomplished by changing it to the light green consistent with the logo, but with an unintended consequence: it fades too easily into the white background. I wonder if people with red-green colorblindness would even see the name at all against the white. At the very least I would move the name and title 1/8" to the left to separate them from the rest of the text, and enlarge the name by 1pt.
HTH .. and hope I don't come off standoffish in writing here.
By no means am I an expert next to you. I really like the overall design and flow of each.
