I've used FireShot for years for it's ease of use and functionality. Save, crop, edit, and print: small areas, or the entire page, with one click. No patching together screen shots or waiting for a copy of your invoice. Page shot, crop and done!
Firefox now has built in full page screenshots with some admittedly slick features, but Fireshot is still the best and most reliable way, which is what matters most for screenshots, and speaks volumes about the high quality and high value of this plugin! Thank you susbox!