I play quite some games on it, and high-end computers are usually cheaper (and better) if they're custom built.
I still didn't build it myself though. Apparently it's not that difficult but I couldn't be bothered and let the shop do that.
A macbook pro for school and work, and an old HP from 2008 for everything else. I don't know what the problem is, but its been acting up for the past year. Now I think its clonked out for good. I opened it up and considered upgrading it, but with all the parts I have to replace I figured I should just build (or have someone else build) a custom gaming PC.