Which one should I wear today?

You have to hand it to Tony Stark. Upon building the Iron Man armor, he didn't just stop. He wanted to continue to improve the suit because that's what he does. He's a brilliant inventor so why would he settle for just one suit? It might be more cost effective to try to improve an existing suit before just creating a completely new one. But since he has a bit of money lying around and likes flashy things, it makes sense he'd keep building new models.
Today, Walt Disney Studios Motion Pictures has released the first official image from Iron Man 3. Production has been underway but apparently principal photography has now started.

It may not reveal anything new but that's okay. The movie's release date of May 3, 2013 is still a ways off. We don't need spoilers just yet.