Computer microphones are improving, but there's no substitute for a high-quality microphone.

I personally use a dedicated microphone with a "pop" filter and a small audio-absorbing shield to prevent echos and outside noise from coming back to the microphone.

Audio-Technica AT2020

I've been using this microphone for years and it's still serving me well. It's affordable and works.

Pop Filter

A pop filter diffuses puffs of air before the concentrated burst of air hits the microphone.

Without a pop filter, you'll end up with spikes in your audio that are very difficult to correct in post-production.

Microphone Isolation Shield

This microphone isolation shield captures sound waves that pass the microphone and it has the benefit of preventing some of the outside sound waves from coming back to the microphone.

Computer Audio Equipment