How to build a gaming Pc that is amazing in performance and very affordable?

How to build a gaming Pc that is amazing in performance and very affordable? - 1

Added (1). Edit
Update: I've been looking into building a gaming PC, but I really don't have a lot of knowledge on parts or how to build one (although I'm doing a lot of research). I'd like to hear some suggestions as to what parts are best for gaming, and how affordable it is to buy those parts and build everything.
I'm currently using this website to help me decide: http://ca.pcpartpicker.com
My budget is capped to $800 but I'm keeping an open mind.

Added (2). Also, I would ideally want my PC to run League of Legends, Minecraft and other games on Steam if anyone was wondering

Dedicate the bulk or your funds to a good processor Graphics card and a SSD If you can afford one. The rest of the parts can be pretty cheap and still do the job well. Just make sure your PSU can handle what you throw at it

You can't have it both ways