Audio problems are a fact of life for video producers, and I’m always in the hunt for the best tool possible. After comparing iZotope RX 3 vs. Audition, I concluded that iZotope is better for both pop and click removal and noise reduction.
You can see screens and hear audio comparisons for declipping and crackle-and-pop removal, here. You can see screens and hear audio comparisons for noise and reverb/echo reduction, here. Here’s a tutorial that illustrates how the programs compare with noise reduction, best experienced with headphones.