I prefer Linux because with Linux, you don't get a homogenized, sanitized, pasteurized, demicrobialized environment. You don't get a single (singularly bland) GUI straddling a barely competent command line. (In XP, the MS-DOS code has died the death. So Windows XP is 32-bit crappiness all the way.)
You get Perl, by Larry Wall.
You get Emacs, by Richard Stallman.
You get a ton of little applications written by real people, along with the source code they commented. Comments can be funny. This also creates a community: Linux users defend our own. We spread the world about our OS, because we are fighting together against the MS Machine, The Bloated Dragon, The Moron-Tyrant, The Idiot-Devil. We have the computer that doesn't crash. We don't have to reboot except to add hardware. We can share diff files to fix bugs in the code, because we all have (or can easily get) the source code to any important programs on our box. We can have fun and make friends and have a chance at meeting the people who wrote our favorite programs. Will I ever get to meet the people who crafted the MS Works Word Processor? No. They are strangers to me, no more real than the people who hew wood and draw water. Will I ever get to meet Larry Wall? Maybe. At least I have his name.
With Linux, using a computer is fun. It is a process of learning. I'm writing an RC4 implementation in Perl, because I got a great Perl interpreter along with my distro. I will release my code under the GPL once it's functional. I would have gladly paid upwards of a hundred dollars for that interpreter, but I got it bundled with an OS sold with an instruction 'Teach-Yourself-Linux' book I bought at Barnes & Noble for $50. Of course, the interpreter is free anyway. All part of the Linux philosophy.
I also have gcc, the GNU Compiler Collection. Again, free. Free of charge, free of restriction. Like Linux. gcc is a tool you could write an OS with. Hell, that's already happened.
Linux is liberated software. Anyone can use and change it. As a result, it has successfully been ported to PDAs, servers, embedded computers, and all manner of other geek toys. Geek toys that are now running the modern world, I might add. Microsoft has an imaginary monopoly. Linux has already done more than it ever will.
Gates is a tinhorn dictator, Linus is a great guy, and I am a hell of a rambler at 0340.