What should I upgrade?

[Transbrak]

Wasn't sure where to post this so if it's in the wrong place feel free to move it.

I have a rig that's several years old and I want to start upgrading it a bit more. It started out as a prebuilt ASUS (CG 5290) that I got on clearance for cheap. I changed the case, added fans, added a Antec CPU water cooler, SSD etc.

My question is where is the smartest place to invest money on upgrades.

It has:
9 gigs of RAM
i7 920
GeForce GTX 260
500W PSU

Any suggestions? Thanks!

[RickyTick]

Definitely the video card and power supply.

[Transbrak]

Anything you would recommend? Would 700W Be enough? As far as the card goes would I see enough of a performance increase in say a GTX 560 to make it worth the money?

[RickyTick]

700 watts is plenty as long as it's from a quality power supply.
I would suggest taking a look at the new GTX660 Ti.