CPU For 680i upgrade from E6600 to ?

[Quint]

Thinking of upgrading....what cpu should I get to achive a noticable boost small, medium to high budget please?

Current spec - factory default

Intel Core 2 DUO E6600 "LGA775 Conroe" 2.40GHz (1066FSB)
EVGA nForce 680i (Socket 775) PCI-Express DDR2 Motherboard
Zalman CNPS9500-LED Aero Flower (Socket 939/754/478/775) CPU Cooler
Creative X-Fi Xtreme Gamer 7.1 Soundcard
OCZ 2GB (4 x 1GB) PC2-8500 1066MHz SLI-Ready Edition Dual Channel DDR2 (OCZ2N1066SR2GK)
Corsair HX 620W ATX2.2 Modular SLI Compliant PSU (CMPSU-620HXUK)
BFG GeForce 8800 GTX OC 768MB GDDR3 HDTV/Dual DVI (PCI-Express)
Samsung 2433bw 24"

COD:WAW see,s a tad laggy at full settings and 1920x1200

XP-SP3 btw (I know 4gb isn't recognised but I went back to xp some time ago and left it in, makes no differance with it in or out)

Thanks in advance!

 

[Quint]

Ok, think I'll look for a guide to overclock this badboy, cheers guys.

 

[Quint]

I've got a new gpu on the way BFG GTX285, warranty replacement.

I know I'm going to suffer with my cpu. Should I think about replacing it now or will overclocking it be enough?

The manual says it supports the following Intel Core 2 Extreme, Intel Core 2 Quad, Intel Core 2 Duo, Pentium EE, and Pentium.

Would it support all the Intel Core 2 (Quad Core) listed on OcUk - http://www.overclockers.co.uk/productlist.php?groupid=701&catid=6&subid=567

Is there a list of compatible cpus anywhere? I'm not overly confident at overcloking, I'm more comfortable buying a new cpu instead.

Any help/advice would be appreciated.