cusconillow :
Rationale, with your reccomended parts list, what do you consider "heavier games?" I just want to get an idea of what the performance of this PC would be.
Also, I have the opportunity to buy a Enermax EG615P - V (E) power supply for $15. Would that be a good alternative to the one you listed?
The R7 250 + G3220 will handle games like Dark Souls II, Left 4 Dead 2, Portal 2, Dragon Age Origins, Skyrim, CS GO, Dishonored, Mass Effect 3, etc. Plus most decently optimized console ports from the PS3/360. That's assuming at least high settings 30+ fps, several I listed should get ultra 40+. It's very playable for a budget build.
However, the R7 250 + G3220 will fall hard on games like The Witcher 2, Battlefield 4, Crysis 3, Metro 2033, Metro LL, etc. You'd have to run at low settings to get decent framerates, and perhaps decrease the resolution. There can literally be a 500% performance difference from some new games compared to other new games.
A GTX 750 is quite similar in performance to the Xbox One GPU, so I'd imagine when Xbox One and PS4 games start hitting more it'd still hold up pretty well at high-ish settings, but the R7 250 would need to be replaced at some point in the next couple years if you want to keep up.
If you have a specific game in mind you're worried about, you can Google it. For example, you could go to youtube and search for "R7 250 Planetside 2" or whatever game you're looking for. If you can't find any people testing that video card in the game you're looking for, try "HD 7750 name of game", as the R7 250 and HD 7750 are very similar in performance, just the R7 250 is a bit more efficient and the GDDR5 versions are a bit faster.
About the power supply... Ehm... I have heard that Enermax is supposed to be pretty good for PSU's, but I'm not sure. It has 36A on the 12v rail, which is a respectable amount, and it has 5 stars on Newegg so it's probably fine.