Noctua NH-D15S - 140mm PWM Fan Dual Tower CPU Cooler - Chromax Black - Intel/AMD
FYI - this is the D15S offset version so can fit round big old GPUs. One of the best if not the best air CPU coolers. It kept my 5900X at around 40C at idle, with 20% speed and around 65C during gaming at 80%, whilst being pretty damn quiet.