Firefox's drop-down address bar is great at getting you to sites after typing a few letters — unless you've mistyped a site or visited similar-named pages. Fix Firefox's confusion forever with a right-click trick in your History list.
Mashable Tech brings us this neat trick to make Firefox no longer acknowledge a site's place in your history. Open up your History menu, choose "Show all History", then either search or click through your recent history to find the site that Firefox can't forget about. Right-click the site, then choose "Forget about this site". Now Firefox knows that you don't plan to head there again any time soon, and it stops showing up in your AwesomeBar results.
10 Killer Firefox Tips, Tricks and Shortcuts [Mashable]