Omg haha is the C2D good for gaming. Dude it destroys AMD's FX series with a tiny bit of OC. It is the best line of gaming right now and it will run circles around any Pentium D out there on the market. Its pretty much the absolute best thing for the money today next to the E6600 with 4mb cache. But now thats out of your budget i bet and mine too. Trust me buy the E6300 and you wont be dissapointed one bit.
Also i know why you asked, about 3 months ago when i got into the whole computer specs and i saw a 1.83ghz CPU...i was skeptical on how would it would be better. But theres 2 reasons:
1 you get TWO 1.83ghz cores packed together to make 3.6ghz of Core 2 Duo Power.
Then you get the new C2D which has all new technology a new fabrication process and everything.
E6300 w/ Arctic Freezer Pro 7 @ 3.6ghz 1.4Vcore
Antec 900 Case
EVGA 750i FTW Mobo
4x1GB of G.skill DDR2-800
2 8800GT in SLI
22" Samsung Syncmaster
1 250GB WD and 1 Seagate 7200.10 in RAID 0
Corsair 520HX 3DMark06 Score: 13900