I have purchased 5 video cards and three motherboards from Evga.    I have had to return an 8800 GT video card and a 7900 GT video card for warranty repairs.  Evga offers a lifetime warranty.  They honor this warranty even if you overclock the part.   You do have to register your product within 30 days to be eligible for the lifetime warranty.
If you need a part that Evga makes, you’ll regret buying it from another manufacturer.