Noctua has become the standard for air cooling CPUs in the last few years. I personally use a Noctua cooler for testing case CPU cooler space due to its massive size. And that has been the only real complaint about Noctua's coolers: the amount of space they take up. To address this concern, Noctua is now continuing their series of single tower CPU coolers starting with the NH-U12S and NH-U14S.
The original NH-U12 and NH-U9 were among the first CPU coolers they ever released, so you can see how long it has been since we had a single tower cooler from Noctua. The new NH-U12S and NH-U14S are only 45 mm and 52 mm wide, respectively, to ensure compatibility with tall memory modules. The fin design of the cooler helps produce a high pressure system for better cooling.
To aid cooling in high performance are the NF-F12 and NF-A15 fans, which boast FocusedFlow design. Combined with six heatpipes, the new coolers focus more on cooling efficiency than size. Add in all the other goodies we have come to know Noctua for--like the NT-H1 thermal compound, 6-year warranty and easy-to-use multi-socket mount--and you have a great package at $64.90 and $74.90 MSRP.