r9 280x vs gtx 770

Really it depends on what games you be playing. A 280X would usually cost less.

GTX 770 will give you 3 free games and has features to aid video recording, encoding, and 3D gaming. Go for it if its worth the premium to you.

On the other hand the 280X is just a rebranded 7970 GHz. Both would perform better in AMD titles like Battlefield 4 and future games using the Frostbite engine (Dragon Age Inquisition, Mirror's Edge 2, Need For Speed Rivals, Star Wars Battlefront, next Mass Effect)
You might find a 7970GHz for the same price and comes with 3 free games too.
 
their both neck and neck in games, or +/- 3% depending on the game. like huilun02 said, if you need cuda for the added performance over opencl in non gaming applications, the nvidia holds a definite advantage over the amd. one thing the amd card does hold a huge advantage over the nvidia card is the 3gb of 384bit vram. if your playing on 1080p this, for now, isn't much of a difference but if you play modded skyrim, or plan on going with a 1440p monitor at anytime, the amd card holds much more significant value over the 2gb vram models of the 770, unless your looking at the 4gb models. down the road with its time to sell the card and upgrade, and 1440p monitors are the norm for the computer world, video cards with more vram will have better value than those with less.
 
im not a big gamer to be honest im going to play on 1920x1080 or higher but im probbaly just going to stick with 2010-2013 games but once gta 5 comes out on pc and the new cod which i hope they will have gta 5 for pc ;3 ill buy them and what card do u think i should get?
 
Then I suppose it doesn't really matter. Minecraft and MapleStory can be played with integrated graphics, while CoD Ghosts and GTA 5 have not been released or benchmarked yet.

So it's between the 770's free games and features, and the 280X's advantage in Frostbite engine games and scaling at higher resolutions