Bike frame material question?

[serene_warzone]

I'm buying a fixed gear bike and i can choose between 2 frames

first one is Chromoly Second is 6061 Aluminum Alloy

The chromoly one is 20$ more than the aluminum,, which should i get?
both bikes complete weigh 22lbs

 

[krm29619]

Aluminium alloy..because it's totally non-corrosive..but it will get dents easily if not taken care..

 

[Mar]

Read this: http://www.sheldonbrown.com/frame-materials.html#ride