RAMs, cheap RAMs

I recently bought a new computer. And... I cheaped out on the RAM. Bought 2x4GB 1333Mhz Kingston Value RAM. I have the exact same build as someone else on YouTube coincidentally, but he's playing a game about 1.5x or 2x my FPS with the same settings. Everything was the same. I'm pretty sure my PSU is not the problem. I'm using a HDD, but he is too, so that's not the problem either. That leaves me with the RAM... It is because of my RAM that bottlenecked my PC performace. If so, which RAM do you recommend for gaming (for other uses, my current RAM is okay)?