23rd
Clean Firefox Address Bar History
The Firefox address bar auto-suggest feature is very useful, but sometime it gets to crowned with many URLs.
You may want to start fresh by cleaning it all using the Clear Recent History functionality in the Tools menu. Select Browsing & Download History and set the time range to: Everything.

OR
You may want to be more granular and delete an individual entry from the History in Firefox. Just highlight the URL (either in the History sidebar or in the address bar drop-down) and press Shift+Delete. Gone, it’s that easy!