My personal opinion now is:
1) EVGA ACX 2.0 (compare price to frequency carefully. Don't spend more than about $360)
2) MSI Gaming 4G
3) Asus Strix
4) Gigabyte Gaming G1
They've actually traded places, but here's some more info:
a) EVGA backplate may be included (not sure) but not pre-installed
b) Gigabyte is longer than some, and currently can't disable fans for 0dB mode (or might be my top choice). Still it's not very loud in idle.
If it updates its firmware to shut off fans (if possible) it probably will be my top choice.
c) MSI was my top choice. I'm currently investigating ALL cards to find out if any particular model is prone to coil whine. Saw several MSI models which had it so it's currently not my #1 choice but it may not be any different statistically from other cards.
*I can't find anything definitive:
http://www.pcper.com/news/Graphics-Cards/GeForce-GTX-970-Coil-Whine-Concerns
d) Asus Strix is nearly identical to MSI, though doesn't overclock quite as high.
Summary:
They are ALL great cards. A lot comes down to aesthetics (backplate, color), fan control, and whether there are any ISSUES.
**COIL WHINE:
It seems to happen only at certain frequencies so reducing (or even raising) the GPU clock speed may help. Setting a VSYNC cap can also help since it may reduce GPU load.