thinking back to applications i’ve used for a long time, snagit comes to mind.  screen shots for a techie are very important and snagit was my first.  since snagit there have been virtualization programs that even let me capture screen shots of a computer booting and utilities in the operating system like paint (again – will it officially make the list or not?) and the snipping tool in windows 7, but snagit has been there when needed.  i especially liked the auto filename feature when i was tasked with capturing many screen shots (maybe documenting an installation routine).  i’ve used camtasia from time to time and again there’s now a version for the mac.