Note: This was written in 2015, it may be out of date now.
There are a lot of commands here which I use
sudoif you don't know what you're doing withsudo, especially where Irmyou can severely screw up your system.
There are many reasons which you would want to remove a piece of software such as McAfee, such as not wanting it to hammer your CPU during work hours which seems like primetime for a virus scan.
I intend this to be a living document, I have included suggestions from peoples' replies.