I've been hearing lots of buzz about Ubuntu the last few months.
My numerous attempts to install on several machines have not been very positive, including last night's Ubuntu adventure. Windows for all its imperfections is still fairly easy to install. Yeah, plug and pray sometimes has issues. My Mac upgrade to Tiger was pretty painless too, come to think of it.
I'm reminded of how my m1400 Tablet arrived: no installation required. Just turn it on and start working and playing.