Just built my new machine this weekend: E8400, Tuniq Tower 120, Gigabyte P35-DS3L, 4GB DDR2-800 SuperTalent, EVGA 8800GT, 150GB RaptorX - All these bought new. I'm using my old Antec Sonata (the original) case, and OCZ 520W PSU (still under warranty).

The new machine was built so I can play DX10 games, as well as be able to run it 24x7 as a web/app server, so it has to be quiet. My previous rig had 6 fans and was very noisy (X-Alien case, opteron 165 @2.7GHz, Asus A8N-SLI, 2GB DDR-400, XFX 7800GTX OC, 150GB Raptor, same OCZ-520W PSU.

Anyway, without wasting too much time, I overclocked it to 400MHz FSB, CPU @9x400=3600 MHz, 1.325 V. Temps are 32C idle, 59 load - with the Tuniq Tower 120 CPU fan at the lowest setting (1000 RPM). If I disconnect the case fan (a single 120mm rear exhaust), the temps increase by 8-10 C.
I'm currently shopping for quieter case fans, and possibly a VGA cooler.
I haven't overclocked the video card yet, so 3DMark06 score is around 11.5K.

I'm very impressed with the Tuniq cooler. I even left it overnight with CPU and case fans both disconnected, and it still managed to keep the CPU below 60C (idle, closed case).