First off, the heck is this PSU? I'd suggest that's the first part you better upgrade.
Then toss in another 4gig of RAM, 8 gig is enough for gaming, and will be enough for at least another 2 years.
A new GPU like a 770 should give enough performance, although if you upgrade step by step, might wait till 800 series drops.
A new monitor will require a new GPU , otherwise you'll definitely see a decrease in performance, as you have to put out in 1080p and not 900p.
// I guess this was an OEM build?
It wasn't OEM ;_; I built it with help a little under a year ago.
Well, that PSU is the result of living in Mexico, not having a big budget, and not having access to big quality retailers of Computer parts.
Thanks for the suggestions! I'll look into buying another PSU today, I guess 600W is enough? I'm also not sure what to look for in a PSU, I'm not really that well-informed ._.
I was kinda worried about upgrading my Mobo because of really annoying stuttering when accessing the HDD (I guess?), so I figured something in my build really needed upgrading.