My old cooler was dirt cheap and died after 2 years of use, so I got a dark rock cooler from be quiet. I think its doing a bit too well.
An i7 8700 running at 4.2 GHz is getting idle temps of sometimes 26c but averaging 29-31 and never peaks above 65-70 even when playing cpu intensive games. Ive only seen it spike above 60 when trying to render somebodies unoptimized blender mesh.
Ive seen posts saying that running below 35 degrees can damage a CPU and most gaming benchmarks ive seen for the same games had the cpu running above 60c.