Hey, why don't we share favorite Firefox extensions here?
Measure It- A draw out ruler for getting pixel height and width of elements on your screen.
Bandwidth Tester- obvious
Add Bookmark Here- makes bookmark management easier.
FoxyTunes- control your music from your browser.
Autocopy- highlighting text autocopies it, like in IRC.
Colorzilla- eyedropper for your browser to pick up colors.
DictionarySearch- highlight text and adds a dictinarysearch to your right click dropdown .
IE View- for when sites are built wrong.
Forecast Fox- tells me the weather in that bottom bar.
Download Manager Tweak- This makes the downloading manager open in a tab instead of a window.
BBCode Xtra- for making things easier in places like this.
BugMeNot- for reading online newspapers without filling out forms.
ImageZoom- Right click on an image and mousewheel zoom it in and out.
Tab Mix Plus- Best tab manager I've seen.
Firefox is better than IE in every way. It doesn't surprise me that more who visit here use Firefox since people usuallly are coming here looking for quality over the other mods out there. They know something good when they see it.
Also, thanks for the tip on using Tab Mix Plus, Rowne. That's a great extension.