Almost any graphics will work with your mobo as it's a standard pcie slot. As above it comes down to budget, resolution, fps, quality settings and games you want to play, along with the spec of the rest of your pc
i don't know what graphic card should i buy for my motherboard(asus rampage IV black edition)
There is no best video card for a motherboard, its all about best card that fits you budget. How much money do you want to spend?
If you have about $700 then i do suggest the 780ti like NBSN was saying though
Almost any graphics will work with your mobo as it's a standard pcie slot. As above it comes down to budget, resolution, fps, quality settings and games you want to play, along with the spec of the rest of your pc