I've had great success over the last 10 years with a pair of Sennheiser 280 HD Pro over-the-ear headphones (https://en-us.sennheiser.com/hd-280-pro). They are great at passive noise attenuation across the spectrum (32 dB) and are extremely comfortable for long periods. It doesn't hurt that they sound great (if you like a flat frequency response) and since they are made for pro DJ and studio use, they're durable and the cord, ear pads, and headband pad are replaceable.

If I don't want the distraction of music, but still need to wipe out the sound of people talking nearby, I fire up https://rain.simplynoise.com/.