For $25-30 the CM Hyper 212+ really is tough to beat and it includes a decent 120MM PWM fan. I use one with my i5 and it easily allows for 24/7 stability at 4.0Ghz. Sure I would like a Thermalright Venomous X or maybe a Megahalem, but they are twice the cost for not a lot more cooling.
Couldn't disagree more. I had a cm hyper212 + with push pull config with 2 3000 rpm fans that would get 82c full load with 3.7 on my i7 930. Put a megahalems on with one low speed fan and dropped my temps 12c.
Really? Doing full load for 24h of OCCT load stability testing at 4.0Ghz I never broke 73c with the single stock fan in my sealed P180 case. I am positive that the Megahalem's of course would do better, but they are over twice the price, I would hope that they would.
Scythe MUGEN-2 Rev B. SCMG-2100 - IF you have the space and IF you have nerves of steel to install it without personal injury to your handyman persona and/or motherboard.
The Thermalright MUX-120 is just $50 - a little better than the Hyper 212+
Tom's 1156 cooler roundup:
http://www.tomshardware.com/reviews/lga-1156-heatsink,2535-14.html