It's getting time to upgrade from my GTX 670, and I'm as concerned about quiet running as performance. When I play StarCraft that PNY card sounds like a prop plane.
So who can recommend a card that doesn't roar under a load?
It's not GPU-specific, really. Not all GTX 670s are created equal. (960s, 290s, etc.)
It just depends on the cooler and your case. The PNY cards I have had with blowers tend to run loud because those coolers tend to be loud. If you have a roomy case and a monster triple-fan cooler, they'll be tons quieter.
Aftermarket coolers are an option regardless - a 960 or 970 will dissipate what, like ~150w tops, right? There are even
passive coolers that are rated for GPUs in that range.
Also, if you're willing to deal with higher-than-average-but-still-safe temps, you can tweak the maximum fan speed settings in the drivers.
You can look at the listings on Anandtech Bench for relative noise numbers:
http://anandtech.com/bench/GPU15/1239
But you'd probably have to go back to the review for the card in question to know the brand and type of cooler - I can only assume that when an OEM (ASUS, MSI, etc.) isn't mentioned, they're talking about a reference card.