I've now got Firefox on three different machines which I use everyday. But my problem is that each one is slighly different because I dont have the same extensions and themes on them. Of course I still use Opera, but with my GNU/Linux setup at home now, I've decided to not install any Open/Free software on it. Which was a problem at first but I've pretty much made Firefox work like Opera now.
First up the ones which make Firefox like Opera for me
Nuke Anything 0.2 – Adds a Remove this object entry to the right-click context menu, which will remove an object from a webpage temporarily. The effects can be undone by reloading the page.
Paste and Go 0.3.1 – Lets you paste an URL from the clipboard and directly load it.
Mouse Gestures 0.9.20040902 – Allows you to execute common commands (like page forward/backward, close tab, new tab) by mouse gestures drawn over the current webpage, without reaching for the toolbar or the keyboard. You can also use “rocker” gestures.
MiniT (drag+indicator) 0.3 – Adds tab dragging with drop place indicator.
Image-Show-Hide 0.1.3.2 – Adds an icon to toolbar. By clicking this button (Or “Shift+B” shortcut) you can simply turn on|off images on all web-pages and (optional) autoreload current page!
QuickNote 0.5.9.2 – A note taking extension with advanced features.
ReloadEvery 0.3.2 – Reloads webpages every so many seconds or minutes
User Agent Switcher 0.6 – Adds a menu to switch the user agent of the browser.
Sage 1.2.2 – A lightweight RSS and ATOM feed aggregator.
Single Window 1.4 – A simple extension that allows Mozilla to fully utilize the built-in tabbed browsing behavior, compatible with Mozilla, Netscape, and Firefox. Singlewindow has only two options: * Single Window Mode — Traps links that would normally open in a new window
And ones I just love
EditCSS 0.2.2 – Stylesheet modifier in the Sidebar.
BBCode 0.3.2 – Adds BBCode/HTML/XHTML formating to the context menu for forums like Mozillazine. Based on Cussers pastequote extension.
Delicious Delicacies 0.1 – Restores our favorite cookie placeholder text.
Wikalong 0.9.5 – A roaming wiki embeded in the sidebar of your browser, indexed off the URL of your current page. It is probably most simply described as a wiki-margin for the Internet.
FoxyTunes 0.5 – Control any media player from Firefox and more… [Windows/Linux]