For ~$250, Jabra Evolve2 75 UC - an incredible wireless headset.
For ~$100, Jabra Evolve2 40 UC - a fantastic wired headset.
For ~$50, Logitech H570E - a very good basic headset with a noise cancelling microphone
Why you need a headset
You want your prospects to think you're legit, right? Then they need to hear you loud and clear.
Shouting into the built-in microphone in your laptop and playing out the audio through the built-in speakers will provide the worst audio experience for your prospects - the microphone is too far from your mouth and you will sound like you are inside a cave. Consider investing in a headset instead.
If you're going to buy a headset
Don’t buy an el cheapo brand.
You're a pro, or manage pros. Invest in a pro-quality headset from Jabra, Poly, Logitech Business or Sennheiser.
Headset wisdom compressed
If you’re a gamer consider that gamer headsets tend to have cheaper omnidirectional (read “capturing every noise in the room”) instead of unidirectional microphones (read “just your voice and no background noise”).
A wired headset is more reliable than a wireless headset and never runs out of battery. A wired headset with a USB connection works better than a wired headset with a 3.5mm connection.
If you are going to use a wireless headset, a Unified Communications or Call Center headset works better than a headset designed for smartphones.
A Bluetooth headset works better when paired with a USB Bluetooth dongle from the manufacturer of the headset. Built-in desktop / laptop bluetooth is buggy and we don’t recommend that you pair your Bluetooth headset to the computer directly.
Airpods and Airpods Pro do a great job of isolating noise coming into your ears but they are less good at isolating noise from your background going into your prospect's ears.