Firefox 2.0 - Thumbs up.

I was reluctant at first to switch... Firefox 1.5 was so great, so stable, so usable... how could it be improved? Five minutes in and it's clear that Firefox 2.0 makes a good thing even better. Antiphishing measures, session restore (if your browser crashes it reloads what you were working on... even blogger posts), Safari-like closeboxes on each tab, a way to reload accidentally closed tabs, shiny buttons and (my favorite) built-in spellchecking. Even the bookmark menu is greatly enhanced. It sports the favicon for each bookmarked site (pikamac.com's favicon is a 1969 Volkswagen) and will display the current title for each bookmarked page (handy for word-a-day pages).

All this at no cost to you.
getfirefox.com

Edit: I was asked awhile ago to share some favorite extensions. Extensions are little nuggets of software that add features to Firefox. First up is Adblock Plus, which blocks banner ads, flash ads... basically all advertising.

Next is Greasemonkey, which I've already spoken about for it usefulness in KoL.

I've just installed Foxmarks Bookmark Synchronizer but it sounds handy for people using more than one computer (one at home and one at work, for example).

CoLT is essential for bloggers: right-click on a link to copy the link and the destination. Shines when I do the movie posts.

I don't use VideoDownloader very often, but it's necessary to save YouTube or similar videos.