which brand is better??

I have had good luck with MSI so far, but have no Zotac cards to compare it too.

I would go with who ever has a better warranty in your area and maybe see what reviews say.

Sometimes you will have cards that use the same board and even the same coolers(but not as common with these 2 companies.).
 
evga, msi, gigabyte, or sapphire. since sapphire only makes amd cards(evga only makes nvidia cards) they are not an option in the 750ti case. in your case, msi. but search around for the evga or gigabyte models and see if they are the same in price. if they are, evga all the way.

if its an nvidia card, i want an evga
if its an amd card, i want a sapphire
but i would settle for an msi or gigabyte if i had too and the price was too good to turn down.
i wouldnt settle for any other manufacture no matter how good the price(realistic) was. obviously if some place like amazon, newegg,etc is going to sell an off brand 780ti/290x for $100, i would buy it.