I'm another Chrome convert. On my Windows machines, it was Chrome/IE8/Firefox/Safari - mainly because Firefox was slow. IE leaked memory, and did some weird rendering tricks, so I gave up on it. IE 9 was worse, causing odd problems accessing our WIKI and other random pages; none of us but those who had to evaluate it downloaded it. Putting it into autoupdate is a disaster in the making. My second choice of browsers varied situationally.
Chrome was fast, slimmed-down and reliable (except for when I overloaded it and it started giving me snap pages, and I had to reboot). Firefox was the favorite of the developers because of useful plugins, but many started using Chrome for general browsing.
On my Macs, I use Chrome/Safari. Both work fine, but I like the common interface across machines, so use Chrome normally. I have IE for Mac (useless), IE in a Windows 7 VM (as a control, or for those sites which seem to work only with IE). My other browser is SeaMonkey (on both platforms), the open-source successor to Netscape Communicator, which I recommend to novices who need to edit internal HTML pages, because of its simple integrated HTML editor. It's also a useful check; when I was in QA (and IE ruled), I used to use Netscape to find web page errors which IE papered over.
