since they're all based on the same AMD / nVid chipset, i'd pick the one that has the best "other stuff", which changes on use. for example, I liked the cooling design and direction of power ports on my ASUS HD7790s so I bought those ESPECIALLY when the local store had both a discount and a rebate on them. in that instance, I paid $80 for a $120+ card.
in the case of my GTX760, I picked the one I did (uh, another ASUS) mainly because it was one of the few in that class that only needed a single 8-pin power connection (instead of most others needing a 6+6 or 6+8 connection). this made it easier for me to manage cables in my tiny ITX case. and again, rebates and in-store discounts made it that much sweeter - but in all honestly an MSI had the same discounts/rebates, so at that point it came down to the single power connection.