At work: Browser - Firefox
Antivirus - ESET Nod 32 4.x
Email - Microsoft Outlook 2007
At Home: Browser - Opera 11.x in Windows [might also try out Comodo Dragon (WebKit-based)], Firefox in Ubuntu
Antivirus - ESET Nod 32 v5.x
Firewall - Software-based.....
Email - No need to install a fully fledged Email/Scheduling client at home. I used webmail services.
Opera for 99% of my browsing, since I have been using it for 8 years I see no need to use any other browser, and Opera mail w/ Gmail.
Then I use Google Chrome for Battlelog.
I prefer Chrome over FF, I suppose the main reason being built in GMail support. But give me any browser that will recover nicely from flash crashing said browser and I will gladly change!
There's a browser I used to use called Pale Moon. It's Firefox, but compiled specially for Windows. It's supposed to be exactly the same (it is), but slightly faster than Firefox on Windows machines.