What is the best computer forensic imaging tool and analysis tool available?

I get a lot of emails and general questions from students and blog readers about what tools I feel are the best to do imaging and analysis. It is no secret that I worked for Guidance Software in the past and have a personal preference for EnCase, but I also use many other tools during my various assignments depending on the type of case I am working and the client's needs.

Here is my simple opinion on the best tool for imaging and/or analysis tool.

The best tool is:
1. The one you have with you (AND)
2. Is mainstream/validated (AND)
3. You have experience using it