The Noctua NH-U12S CPU cooler is one of the very best air coolers available.  It’s a big beast with 140mm fan, meaning you need to check if it will fit in the case you want.  Call or email to check first.  Overall, with such as large fan, the cooler is very quiet.  When tested against similar sized alternatives, it offers superior cooling performance, which means you can run it more slowly for even less noise or it gives you headroom for potentially higher overclocks.