Gentoo :3

Nah, for the average computer user, Windows 7 is the best OS. Obviously, there are other OSs that are better for people with specific needs, but Windows 7 is the best choice for most people, since it's fairly easy to use (even Ubuntu is off putting to many), most programs are made for Windows, it has driver support, and it isn't Vista. XP is also a good choice, but it isn't being supported much any more. As long as Windows is the market standard, the latest non-POS version will be the best choice for most people precisely because it's the standard.

Why specifically Ubuntu Linux? Why not Linux in general? There is more to Linux than Ubuntu.

lol, sorry but I feel that ubuntu represent Linux's most famous OS, but that is just me.

But when Google OS comes, Linux may show its importance to the world.

I've already tried the Google OS. It's basically just a browser, that's it, no desktop at all.

OSX:  OSX has the benefits of a *nix backend combined with Apple's software suite and Apple's aesthetic UI.  I used a Mac-Mini for about a year and my experience was fairly positive.  Growing up on PCs means there were a few things that weren't immediately familiar to me and a few things that took a little more doing than I'm used to, but nothing major.  My only real complaint is that there are a lot of Windows-only applications and games that you don't have access to in an OSX-only environment.  As a result, I would never run OSX standalone.

Linux:  I've used a lot of different linux flavors and I've been modestly happy with all of them.  The benefits of *nix backend are always nice combined with rich package repositories (almost regardless of distro these days) is great.  Inconsistent UI and bugs are major problem though.  It may be graphics anomalies and process issues in one version but sound issues in the next, but it feels like there are always bugs.  You have a non-VM solution to Windows-only stuff in WINE but it's not reliable.

Windows XP:  I have no real complaints about this OS.  Having used it for the better part of a decade, I know my way around the OS fairly well.  I don't install 5 metric tons of garbage like some people and, since I know where the services and the rest live, I know how to keep my machine running lean even after installing things.  Pretty much any complaints you'll see about Windows XP aren't issues at all for me.

Windows Vista:  Basically Vista is more secure than XP (which really doesn't matter if you're a smart user to begin with) but comes with higher spec requirements.  If you're running older hardware then you'll have some issues but otherwise it's a solid OS.

Windows 7:  It's all of Vista's beauty without the heavy hardware requirements.  It's highly compatible with a lot of games too.  I'll probably be running it in the very near future so I'll have more comments then.

Verdict:  Windows XP.

don't have a best for me, they each have shitty problems, it's like choosing the best color in a pile of different stacks of shit, can't do it.

Debian Linux, however because of games I also have xp, but I use it only for games that doesn't work on dosbox or wine.

Such limited options... But I guess I'll say say Ubuntu anyway, since the core isn't any different from any other Linux system.

That said, there are two reasons for sticking with Windows here: software support (especially games) and that my WLAN adapter isn't working too well in Linux, not without irritatingly much work at least. And while the latter could be fixed, don't forget that I have another reason as well.

XP so versatile.