Haswell-Broadwell or FM2+ or AM3+?

Hey i'm building a new PC and im stuck on choosing a CPU I'm only gaming on this computer. Im deciding on FM2+ or AM3+ or LGA 1150 so i can go from haswell to broadwell?

 

Upgrading one generation probably won't be worth the cost. I would go with an i5 4670k or fx8350 paired with a decent motherboard with overclocking chipsets (z87 and 990fx). Or you can consider xeon e3 1230 v3 and a midrange motherboard with H87 or B85 chipset. That xeon part is an i7 4770 without IGPU, so you will get 8 threads under a budget but at the cost of little or no overclocking feature.