Well first of all A is a reference cooler design which should be where you make your first decision. Non-reference coolers, as in the second two, will operate cooler and quieter, at the expense of ejecting the hot air into your case. This isn't a problem at all if you have decent ventilation, but for smaller form factor cases or cases with really cluttered wires and poor airflow, reference is a really good choice because it exhausts all the air out the back. EVGA is a really good brand. Each of these cards differ about 1" in length, so that's also a consideration.
I can't wrap my brain around WHY the Galaxy card is $42 more than the Gigabyte, so this isn't even a question. Yeah you get a slightly higher core and boost clock, big deal. Out of those three, get the Gigabyte card.