all depends really. I am in the process of writing a guide/review of all available options within reason.
I can tell you the short of it right now.
Dxtory's Directshow output into a streaming program (OBS,FFsplit, X-Split) will give anyone the best quality and least amount of performance impact shy of using a dedicated capture card. It is hands down the best method available. It will also work great with any game and whether you use crossfire or SLI supports windowed and fullscreen, it is basically flawless and perfect and worth every penny.
It is better than using the game capture in obs or xsplit, it is dxtorys ace in the hole and why so many people use it. Also the only program that offers this feature.
Secondly, I can say that for free OBS is probably the best solution you can get for actually streaming content. If you're willing to spend some money, then in all honesty X-Split is more functional. The features are easier to use, and provide more functionality. That said, it is debatable that those features are that much better to justify the price of X-Split. If X-split was 9/10, I'd say OBS is 8.5 /10 and it is free. OBS would be the winner clearly. I use X-Split though, because of the extra functionality.
Some other tips:
If you want a twitch chat overlay
in your stream, then use
CHATTY.
If you want a twitch chat overlay
in your game that you can use while in game use
Trillian.
I will work on getting the guide/review setup. I tested, OBS, FF-Split, Action!, Raptr, Overwolf, Playclaw and X-Split broadcaster and X-Split gamecaster.
Nothing has the features of OBS and X-Split broadcaster however.
Gamecaster is pretty neat in that while in game you can hit a hotkey and draw on the screen which would be cool for some people who do in game streaming guides.
Here is OBS + DXTORY at 1440p all ultra 4xmsaa and high post process AA streaming at 720p/30 fps with dxtory and obs. think it was the x264 codec.
http://www.twitch.tv/the9quad/b/601847927
that is how well dxtory does.
here is chatty and trillian
http://www.twitch.tv/the9quad/c/5760474