You said "running very heavy graphical games".
IMO you ought to get one of the following.
1) AMD x2 3800 AM2 Socket
2) Intel E6300 or E6400
Make sure you get the AM2 socket if you go with AMD. Essentially the only difference between the 2 Intels is the stock CPU speed, though the multiplier on the E6300 is x7 as opposed to the E6400 x8. In addition the Cache is larger on the E6400. The cost difference is about $50.00. The choice is yours.
If you OC, then both can be taken to psuedo-E6800 speeds
More importantly for gaming than the CPU is your GPU, graphics card. At this point in time I would go for 7900GT or the X1900XT (Ithink, my ATI knowledge sucks). That class is better to for maxing settings out (if possible).
[SIZE=\"1\"]E6400 @ 3.4 , Noctua 120
7900GT @ 670/1680 , VF900
2 x 1GB Patriot 6400 @ 425
WD SATA 250GB
Neo HE 550
P180 / G15 / MX1000[/SIZE]