I have:
Asus 7790s
MSI 7870
XFX 7870 Double D
XFX 7850 Core
Sapphire 7870
I like MSI the best. Yes, they have hideous coolers which are very loud at higher RPM, but they seem to have the most efficient cooling. My MSI card is the most silent and the coolest of the bunch.
XFX on the other hand has the best warranty (Double D version has lifetime warranty) but their cards run extremely hot at stock speeds which is a shame because they seem to be great overclockers (both 7870 and 7850). I have mine cranked at 100% fan speed and I can hardly hear it over my other fans. Also have an XFX 7850 Core edition. Card overclocks great at stock voltage, runs hot, fan is not very loud.
Sapphire 7870 seems like a cheap build to me, it is in between XFX and MSI as far as cooling is concerned but it seems to make a lot of noise at certain fan speed %.
I love my Asus 7790s. They run cool and silent and the build quality seems to be pretty decent.
Temps are big for me, and if XFX started putting better coolers on their cards, they would be a #1 contender for me. In the meantime, MSI gets my vote because I know they have great customer service/warranty because I have RMAd a bunch of motherboards about a decade ago. Hopefully their service has not changed.
I have not tried Gigabyte although I am looking forward to trying them out, looks like they have really good coolers.