I'm currently using Klipper, and it's fine, I suppose, but I miss the ability to cycle through the previous clips with simple keypresses, like in the emacs killring (the only thing I miss from my very brief experimentation with emacs back in the day).
You can use Play it slowly, which is rather bare-bones, or Sonic Visualizer, which is something of the opposite, but quite powerful.
My daily workhorse is Transcribe!, which I've been using for nearly 30 years, actually. Very powerful, and very intuitive, and with a lot of useful effects, such as filtering out the vocals (if possible), etc. I paid a one-time fee for a subscription back in the day. Money well spent.