Any, all are 3 yr warranty.  The xfx has a rebate but the fans might suck.  Also you can buy 5 of the xfx.  I am a asus fan boy and I have had good luck with their fans.  Honestly all are pretty much +/-1% equal in performance.  Fan life, memory type and cooler design are the variables here.  I'm too lazy to look all of that up to help you.

If your strapped for $ go cheap and get the rebate, not to mention buy more now... or go for the other 2.