Where to put my money?

I am upgrading my mobo and I have about $150 remaining. My hardware is listed below. Where should I spend the rest of the money? I was thinking PSU and maybe a Ninja CPU cooler. Otherwise Id just save the money I suppose.

Intel Pentium D 820 2.8 ghz dual core
Asus P5WD2-E Premium
2x Corsair Value Select 1 Gb DDR2 533 memory (2gb total)
XFX 7800 GTX 256Mb Nvidia Graphics Card
Antec TP2-550W Power supply
ZALMAN CNPS 120mm Copper LED CPU Cooler

i say stick where you're at until you need something better, your rig's fine, just overclock your cpu

If you don't already have an 820 you might consider an 805 and Ninja cooler. Then push that CPU as high as it will go and I bet it will beat the 820 anyday of the week.