I want to buy a graphics card for the best price to the value that can render video good. Which would be better a 760 4gb or a 770 2gb?
770 2GB has more performance. The 760 4GB is a little pointless. The 660ti could render video better than the 760. The 760 isn't much of a productivity card, it's just a card that's geared to 1080p gaming.
Depends; if you're on dual 1080p or 1440p id go for the 760 , it will be better all round, otherwise get the 770.
It would take 760 sli to run a larger display config.