To be honest, the general consensus among hiring companies and executives out there is that one year MBA programs are "MBA light." Unless you are going to stay with your current employer and simply use the one year MBA to leverage your advancement, I would opt for a 2 year program, which will carry more credibility with recruiters. Even though your resume will say MBA for either one, the dates will give you away. If you have the time and money, go for the 2-year and you won't regret it.

The only thing I will add is that the one year MBA seems to be preferred by business undergrad majors as they have had some education in these topics already.

Good luck!
Aveek Guha, President, www.mbadaycamp.com

Both are good and moreover it also depends on your preference that which one you want to join. If you have required industry experience then 1 year program would be better for further career growth. Moreover if you don't want to leave your current job for further studies then online MBA is also an option in front of you which so many top universities have started these days.