Firefox
The first time I mentioned Firefox on this website was because it had crashed and I had lost a post that I had written. Indeed, looking back at what I have previously written, it is clear that Firefox often only enters the picture when it is misbehaving.

This does not mean that I do not like Firefox. While it seems to have become cool in some of the circles I run with to prefer Opera, because of its speed, I think Firefox's extensions, open bug tracker, and other features are a more compelling featureset.

Still, Firefox sometimes crashes. In its developers' defense, this is almost never the fault of Firefox, but is because my settings profile became corrupted, or I installed a misbehaving Greasemonkey script, or (most recently) because I was using an unstable nightly build.

This evening, I was writing a response to someone's problem with compression on the Gregarius forums when I made the mistake of opening an InformationWeek article. For some reason (maybe connected to their advertising?), all InformationWeek articles - including one lambasting Firefox for memory problems - cause a crash:
Gnome application crash dialog
Luckily, the Firefox build that I am using includes support for restoring sessions. I had assumed that Firefox just gathered information on the URL open in each browser tab and restored this after a lost session. But no! My form data was stored as well, allowing me to continue my response where I have left off. Brilliant!
Firefox restores the data lost from when it crashed.
It has been said that Firefox 2 does not include features that will allow it to continue gaining market share after Internet Explorer 7 is released.[1] While the inclusion of tabs in IE7 might cause some people to decide not to switch to Firefox, new world-changing features like session restoration will continue to attract users, especially as the Internet becomes even more integrated into desktop technology.

--
[1] I cannot find the article I am specifically referencing here, and the only piece that comes close to the anti-Firefox vitriol of the original is from InformationWeek. Personally, I think my browser has crashed enough tonight.