Poll: What OS do you use?

What operating system do you use on a day in, day out basis?

I want to know your optimal environment, as most of us use at least two OSes weekly or daily.

I'm going to stick to just one option for Linux; feel free to elaborate on distro/wm/environment in the comments.

(FYI: It's been a year+ since there the last poll of this nature and traffic has doubled since then, so I think it's allowable :-) )

Archlinux with AwesomeWM or Xmonad, urxvt, chrome browser or uzbl for browsing.

I use Windows XP at work. At home, I have Windows 7 on my desktop computer (a Dell Dimension e520n) and Ubuntu 10.04 on my netbook (Lenovo IdeaPad S10).

Firefox is my browser on all three.

I used to use FreeBSD and switched later to Mac OS X (never really liked it though), which made me quite lazy. After my macbook pro gronked out, I switched back to Windows out of convenience. Besides I wanted to play some games again and had a few applications that would have required emulation, so I swallowed the (once) bitter pill and installed Windows again and I have yet to regret it. Been using Windows 7 x64 from the beginning (MSDNA) and I haven't had any problems. So, this is me, using windows 7.

Serial consoles... Bah! Get me a 3279.

Actually, I would really like a 3290.