I managed to get a 4.5 overclock with a Corsair H55 alongside a Corsair 500R case (which has great airflow). Keep in mind that cooling is going to be the most personal aspect of any PC build. It is heavily influenced by ambient temperatures, so if you live in Texas and have 110 degree days and no AC, your cooler will not perform nearly as well. Furthermore, certain cases do a much better job with airflow; the most basic being big cases versus smaller cases.
I went with the H55 because as a liquid cooler it puts much less strain on the motherboard, is noticeably smaller when compared to other CPU liquid coolers so case space was less of a concern, and has no software or firmware to worry about (which I think still needs time to mature). It is competitively priced versus the NH D14.