I just picked up the Cooler Master Hyper TX3 for $22 from Micro Center and I'm thoroughly pleased with it. It's a tower style heatsink with a 92mm fan on one side and additional mounts for putting an optional second fan on the other side. The fan is PWM, which I don't usually like but this fan runs quiet so I don't mind. And this fan does run quiet, nice and quiet.
The back story is that I had an AMD "black edition" heatsink that I put on my lowly X2-3600. The thing makes a very unpleasant sound. I got a heatsink with a 92mm fan that claimed to run at 18db. The thing did NOT run at 18db, it was probably closer to 30db but I really have no idea. Regardless, it was too loud for my tastes. Took it back. Grabbed an Antec 80mm fan with three settings and planned on putting it on the AMD heatsink. Oh, crum, I come to find the AMD heatsink is 70mm. 70mm? Come on AMD, that flocking blows. How daft of you; you put a half-decent heatsink in the box with the Phenom II X4 black, but you put a 70mm fan and fan mount on it. Jerks. So, I take the Antec fan back and was all set to grab and big 120mm tower-style heatsink when I see the TX3 sitting on the shelf, daring me to spend less. I took that risk and it payed off. No giant 120mm cantilevered kilogram here, thank you.
The TX3 seems to provide exceptional cooling at an exceptionally low cost and noise level. The only issue I had was how dang hard it was to push down the retention lever. I actually had to put on gloves so the metal lever didn't dig into my thumb. And, I saw once I put it on that it was only half engaging itself (don't ask), so I had to do it twice. Unhooking that lever was harder than hooking it. But it was worth it. My stock clocked x2-3600 claims to top out at 42c while stressing both cores to 100%. And the fan either doesn't speed up to keep it that low or it doesn't create additional noise when speeding up.
It is decent enough that the thought crossed my mind to replace the 120mm behemoth Scythe Ninja in my other box with one. The only reason I don't is the additional $20 that'd require. I'd trade that thing for a TX3 though
I'm starting to sound like a viral marketer... but, the TX3 deserves a good plug. Coolermaster Hyper TX3: very strongly recommended.