Need help choosing a good gaming rig!

Hello!

I'm currently studying for my exams which start in May. I've struck a deal with the parents where if I get good grades throughout my exams I can get a new computer, as my current one is doing my nut in. My local PC shop can build one for me, I can choose the specs I want and the guy will work out the overall price for me and all I need to do is pay for it and wait! This is why i'm asking for a good rig that I can use to play my massive library of Steam games that I can't play as my PC is about 6 years old and cannot run even Minecraft that well. So I ask you, mmohut techy tech tech-ers; Recommend me a good gaming rig!

Thanks.

you can make up a descent build on your own, make sure you dont lose that bet

Here's a build I'm getting with my income tax refund. I save about $350 building it myself.
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