EVGA is best for warranty/support. The FTW model performs equal to other cards like the MSI TF4 and Gigabyte Windforce and ASUS DCII TOP
ASUS and Gigabyte offer the best overclocks apparently
MSI always makes excellent coolers.
Basically those are the 4 brands you want to consider.
Me myself I bought the basic vanilla 670 from evga, sexy black n white is what convinced me to buy
ASUS/Gigabyte/MSI offer 3 year manufacturer warranty
EVGA has 3 year limited warranty with the option of buying 5 year protection plan for $20 extra or 10 year protection plan for about $40.
EVGA also offers advanced RMA for you to buy so incase your card fails they will cross ship the new card to you before they recieve the defective card so you will have your system back up and running much faster. As well they offer the step up program which is very nice.
Noise wise, any card will run loud if you set the fan speeds too high.
My vanilla 670s run at 60% fan speed max (can't hear the fan at all) and stay relatively cool and extremely quiet. Same can be said for the rest of the cards.
Vanilla 670s exhaust all of their heat out the rear of the case so no heat is dumped back into the case/other components (good case airflow makes that not an issue)
The ASUS/GIG/MSI cards all exhaust their heat back into the case so you want to make sure your airflow is proper.
Basically I will tell you as simply as I can
get whatever card looks the best in your system.
DCII for sexy black n red
TF4 for sexy black n blue
WF3 for meh not too sexy but goes with pretty much any system
FTW sexy black/green
Vanilla sexy black/white
If you are wanting to OC the card as high as it can go
ASUS/Gigabyte are best bets