Linux, windows, macintosh.

[Cale_Hagan]

which do you have, which do you use on a frequent basis, and which is your favorite? the poll is on favorite...

Mine is windows 7, just because i do a lot of games, and for ease of use. i know i know.... kind of a weird statement. i also love Linux, i just need to start using it more... that's what i have on my netbook, had 7 re installed for Linux. i love it because it is not a resource hog.

[x88x]

I have two systems at the moment that run Windows. My main desktop runs Windows 7 because I use it for gaming and I learned a long time ago that dual-booting a primary system is pointless (because I end up spending all my time in one OS anyways). The other system is my dedicated folding box running Windows XP, but that's just because GPU folding only works in Windows.

Every other computer I own runs some version of Linux. My laptop, my fileserver, my SSH portal, hell, even my router. On my laptop I run Ubuntu because that's what I'm most familiar with (not too happy with some recent design decisions they've made though, so that might change in the future), on my fileserver I run Ubuntu Server because it's a bit easier to do a few things with than Debian. Any other servers and/or VMs, I usually use Debian because it's very lightweight and stable and I'm more familiar with the Debian/apt architecture. I do from time to time find another distro more useful, however. For live-CDs I have a certain soft-spot for DSL and Puppy, for example.

EDIT:
To expand on my choice of Linux as a preferred OS, these are the main reasons I prefer it:
1) It's OSS. In other words, there's no licensing to worry about, I don't have someone else telling me how I can and cannot use it, and in using it I am supporting a design and production philosophy that is all too rare in today's world (see my sig).
2) It's free.
3) Control originates from the CLI, not from GUIs (not to say there aren't GUIs to do most everything, but the GUIs hook into the CLI commands instead of the GUIs directly reaching to the system with no way of doing it from the CLI like most of Windows is designed...and yes, I know about PowerShell, but that's a relatively recent change).
4) It just damn works for me. Keep in mind that most of what I do with computers outside of the browser and gaming is stuff that either started out being done on *nix systems anyway, is just as easily done on any OS, or just is not exactly easy to accomplish on the Windows architecture because of inherent limitations present in it. Go ahead; try putting a wireless interface into monitor mode in Windows. Let me know how that works out for you.
5) It's almost always a lot lighter on system resources than Windows.

[AmEv]

If I could, I'd be running Kubuntu on all my machines.
My desktop runs XP pro.
My laptop runs Ubuntu 11.04 right now; Kubuntu is a bit system-heavy on it right now....

[Twigsoffury]

Windows 7 UL x64 / Windows 7 SP2 x86

dual boot.

[DynamoNED]

My OS of choice is Windows 7 64-bit. For me, edition (Home Premium, Pro, Ultimate) doesn't matter so much: If there is some feature I need, I can probably find a legit app or utility for free that will do what I need. I use Windows on most of my PC's for games as well as compatibility reasons.

I also admit that there is a lot to like in Linux, as well. In my undergrad Comp. Sci. work, I learned most of the basics of Linux, as one of my professors made us do almost all our work by ssh'ing into a server running Fedora using Putty. CLI C/C++ compiling has its quirks, but it was a great learning experience. These days, when I do use Linux, though, I prefer something with a nice GUI, like Ubuntu. My favorite part of any Linux distro: It's great for resurrecting old hardware. I had my parents' old computer from 2001 (1.4Ghz P4, 256MB PC800 RDRAM)running as a little Linux file server and for its age, it zipped along just fine, until the 9 year old HDD finally gave out. (What was it running before Linux? Windows ME. /Shudder...Scary, I know.) I just bought the replacement drive, which should be arriving next week.

[AmEv]

The REALLY nice part about Ubuntu? Unified package management.
I do understand that there are few virii because it's not THAT popular.
But, I always find it's lighter than Windows 7, definitely on battery, especially on HDD space.

[TheMainMan]

Windows 7 64-bit for me. Hard to argue with the price of FREE! MSND-AA through my school for both desktops, came pre-installed on my laptop. Laptop is Home Premium, desktops are Pro. Love the integration of WMC so that it plays nicely with the Xbox 360.

[CorsePerVita]

Still using XP for my gaming machine but we use linux/mac at work quite a good bit.

[luciusad2004]

Oh man... Only person to select Mac OS X.
I guess I'm the minority but I've just always found it pleasant to use for general use. (browsing the web, dicking around, etc.) It just feels like a very well polished *nix box to me. That being said, I don't own a mac at the moment and primarily use XP because its what I have and I like to have at least one Windows machine in my home.

A close second if not equal would be any Linux distro. Though last time i tried out the latest version of Gnome i wasn't liking it all that much and actually felt pretty unhappy with my Ubuntu box. I started using XFCE again but haven't been using my desktop lately as my laptop is a bit more powerful and performs better.

Edit: Once I rebuild my PC i'll probably be throwing Windows 7 on it for gaming and then possibly installing Ubuntu on my laptop for general use depending on compatibility.

[x88x]

It just feels like a very well polished *nix box to me.

There's a very good reason for that.

Personally I've just never really meshed with OS X. Partly because I've never been able to bring myself to buy a Mac, partly because I don't like the idea of having to hack on an application management system in a *nix OS....and not having the ability out of the box to compile my own stuff if I want to.