I've never come across a better tool for analyzing and auditing websites. I've been using the entire SEO Powersuite of Website Auditor, Link Assistant, Spyglass, and Rank Tracker.

It's a joy to use (like the entire Powersuite is), and the reports are completely customizable. It gives you all the info you need. Read all the other reviews, it's all been stated before.

Some may see it being a desktop program as a con - I think it's a neutral issue. Sometimes I'd rather work in a web interface, but the reason it's so powerful is because it runs on your desktop. I'm positive that they'd have to take away a lot of features and charge a lot more if it was a web interface.

I still use Screaming Frog, but Website Auditor and Screaming Frog serve different functions for me. If I need a simple list of pages on my site, or something like that - it's easier for me to just throw the URL in Screaming Frog - but when I want more robust information that is so nice to look at, and make great reports? Website Auditor all day.

Seriously, this is the best auditing tool out there. Buy, Sumolings, buy!