Depends on what you'll be using it for. The FX-6200 is slightly newer and performs similarly to the FX-81xx CPUs in gaming. However, I wouldn't go for either. The new "piledriver" cores are getting released soon so I'd wait for those or otherwise go for an Intel chip.
I sometimes render out videos but it would mainly be used for gaming
6 or 8 cores can come in handy if you are encoding video and if the codec you use can make use of multiple cores. For example, the x.264 codec can take advantage of 8 core (if I am not mistaken), however, if you encode videos using the older XviD codec then 6 or 8 cores are overkill since XviD can only use one core (despite claims of being multi-threaded).
The vast majority of games only use 2 core. Games capable of using more than 2 cores represents a small fraction of games released every year. BF3 is one of the very few games that can make use of more than just 2 cores; but only in MMO mode.
GTA 4 is an example of a game that does not use two cores, but it can benefit from a quad core CPU. That's basically because the game is so poorly ported from the console version that it basically hogs up nearly all the processing power of 2 CPU cores. Having a quad core means that Windows processes can run off of the 3rd or 4th core so that the plays a little smoother.