They are all nice. But the first one to me looks a little bit on the plain side being all white. It has that 'I did these myself and printed them in my inkjet printer' look to it. I could probably do that one myself.
To me the third one with the curves etc is something that would be a lot more difficult for me to do myself. Giving it more of a 'professional feel'.
The third one looks very professional I would go with that one. I second changing the gmail and getting your own domain. If you are going to get your own cards you might as well, it is a wise investment.
Late to the show, but 3rd design is quite nice! I agree on ditching the gmail email, but pick up a google voice # if you're using your mobile #... at least you'll be able to tell when the caller is a business caller and answer appropriately.