I use Firefox mainly because of the tabs and extensions. Ever tried ForecastFox or FoxyTunes? They always come up pretty handy for me... And IE doesn't have a plug-in selection as wide (or good) as the firefox extensions...
And I think that Firefox's pop-up blocker is better than IE's, afaik.
I also use Thunderbird, although they should release a new version, this one is getting old... I started to use it to avoid Outlook Express' exploits. Now, with SP2, OE got MUCH better, but I'm sticking to Thunderbird... Old habits, you know
