These are the values I change to make my Firefox browser fit my needs:

^Item ^Value ^Effect^
|browser.urlbar.autoFill|FALSE| Disables autocomplete of url's (e.g. 192.168.5.1 makes Firefox autofill 192.168.5.108, causing me to go the wrong URL)|
|browser.urlbar.trimURLs|FALSE| Shows current protocol in URL bar. When enabled it removes the protocol definition. Am I using FTP, HTTP, HTTPS? I don't know, but with this disabled I do.|
|dom.disable_window_move_resize|TRUE| Disallows javascript to resize browser windows. Windows flying around being resized is often frustrating, so none of that for me|
|dom.event.contextmenu.enabled|FALSE| Disallows javascript to remove the top menu, disable rightclicking etc.|
|browser.backspace_action|0| Enables press of the backspace-button to go back one page.|
|browser.showQuitWarning|TRUE| Activates a prompt asking to save tabs or not when exiting Firefox. This is nice when accidentally hitting CTRL+Q instead of CTRL+W.|
|geo.enabled|FALSE| Disables geo-location feature. I know where I am. Services do not need that info. If they do, I'll enter it for them manually.|
|<del>browser.tabs.onTop</del>|FALSE| Puts tabs below the menu - **After FF29, [[https://addons.mozilla.org/en-US/firefox/addon/classicthemerestorer/]] 'Classic Theme Restorer' is needed to move tabs below the menu**|
|browser.newtab.url|about:blank| Removes the Firefox "tiles page" when opening a new tab. Instead displays 'about:blank' (blank/empty page).|