A professional, high-quality voiceover requires professional, high-quality recording equipment and editing software.
Here's what I use in my studio.
It starts with a quality microphone
While I have a number of excellent mics by Sennheiser, Shure, and Electro-Voice at my disposal, my go-to mic of late is the Rode NT-1, noted for it's flat, neutral response that's excellent for a wide variety of voiceover applications.
A little louder, shall we?
I use my trusty Symetrix 528e mic pre-amp to supply power to the mic and boost its signal, as well as to add subtle de-essing and compression.
This thing is a workhorse; I've had it for ages, using it in studio and live applications, and it's never let me down... and it sounds great!
It's time to convert
In order to get the sound of my voice into my audio editor for editing and final processing, the analog signal needs to be converted to the bits and bytes understood by a computer.
For my interface, I use the Focusrite Scarlett Solo.
Finally, a little spit and polish
The last step before your voiceover audio is ready to be delivered is for me to edit and master the audio for pristine sound quality.
I use Adobe Audition for its ability to make seamless edits, as well as its wide range of audio enhancement features. Your audio is delivered to you sounding exactly as you want.