I would rate this a good 8/10 for gaming. If you want to upgrade i suggest you could get a high ghz proccesor and crossfire 2 gtx's at the moment you could play most mid range to mid-high range games at ultra graphics with 60fps. and High end games at high res med-high graphics. also i suggest for high end gaming you upgrade to 16GB RAM
Have you already built this ? if you have then im sure it will do fine but if you havent i would change the i3 to an i5 if you can or if your budget is low i would go with an amd option. i am not a fan of the i3.
With the lower end intel processor and the relatively small HDD I'd give it a 6/10. Don't let anone knock your PSU. After all it's better to have it and not need it than the other way around.
No one is knocking anything. But when factoring in a rating between 1 and 10 (a rating he asked for, mind you), one would have to be a colossal moron to overlook the fact that his PSU isn't even close to being efficient for his particular build.