Technically speaking, the FX-8150 is the best since it has 8 cores. However, the vast majority of games only use 2 cores with a small fraction capable of using up to 4 cores. Therefore, if gaming is your primary concern then 2 of the cores will be idling most of the time and 4 cores will be idling all the time.
None of the things you are doing (other than a possible game) will use more than 2 core.
The third link is the best in my opinion, simply because it has 6 cores and the price is great. About half of the games now (including Minecraft) still use only two cores, but that's changing very rapidly. Most games will start to run off of four cores, MW3 already runs from four cores.
I think the third link is best for your situation.