Original Screenshot Pimp (2.15) patched for Firefox 1.5 - 20.* Rated 5 out of 5 stars
Here is the great original Screenshot Pimp (2.15) before it was loaded with the Bing toolbar and Facebook garbage. Working in Firefox 14+.
On first install you may have to go to addon options and disable toolbar button if you want right click only. To install, extract the RAR archive, go to Add-ons, click the gear button, and click Install Add-on From File, then select screenshot_pimp-2.15-fx.xpi. I hope the author can recognize that most people do not like the new addons.