Symbian OS is for smartphones. XD
I'm a mac user, with a Windows 2000 desktop (that amazingly does run faster than my parents' Windows XP desktop), and I have used Linux in the past... but only for server installations.
I used an old version of Red Hat, and SuSE Enterprise 9, and I must say, they're some of the best server OSes I've used. Although I've never touched a computer running OS X Server, Windows 2000 as a server, with IIS and Microsoft SQL Server, sucks. =P
However, if I plan to be gaming (what? me, gaming? impossible! *coughcough*) or running most applications, I like Windows 2000 just fine. (It saddens me that, in a few years, most developers won't be supporting Windows 2000 anymore, though.)
Just my two cents on non-Mac operating systems. =D