Hello!
The choice of which is better is really up to you, they have different features but should perform at about the same...
Gigabyte:
Usually cheaper
More Environmentally friendly
Claims to have a better HDMI connection
MSI:
Has better cooling (Twin Frozr III)
They usually look a lot better
Usually more expensive
So you have to ask yourself the question, do you care more about looks, or more about price? Do you care about the environment or do you care about better cooling? The decision is up to you
-Duffy