good heart rate monitor/watch

Hi-- I want/need to be able to track my heart rate when I exercise, and sometimes at rest. What device do you guys recommend for this purpose? I currently don't own a fitness tracker, and really am not interested in getting one to track calories burned, for instance. I guess I'm mostly interested in a watch, and preferably not several hundred $$ if possible.

I'm currently down with something, but when back up to running more, that's what I would mostly be using it for.

Thanks!