I am now a complete convert to Ubuntu for desktop systems. After 6 months of use, I am running it at home, on my laptop, and at work. For the laptop there is no contest, as I don't do Fedora or SuSE, and it is just too time-consuming to configure all the power management daemons, battery and wifi applets on Debian to get sensible enviroment (in particular, rt2500-based WLAN cards, in my case the Asus WL-107g, work out-of-the-box on Ubuntu 5.10, and with the help of Ubuntu's wiki worked fine in 5.4 too).

For work, having a current version of OpenOffice without hassle is a big win. And for home, having a supported AMD64 version gives it the edge; plus the UTF-8 locale support is much more complete. I even found myself on Friday forced (by time constraints) to use it on a machine doing server tasks at work, and found that it ran the software needed just as well as Debian, my usual choice (expect for one compile glitch, which was a real bug exposed by gcc 4). (I should qualify supported, though: only the Ubuntu core is supported, the universe and multiverse repositories, which just make available Debian's wider range of packages, are only unofficially offered by Ubuntu.)

My only complaint is the upgrading between releases. It seems poorly documented, and when run from within synaptic on my laptop at work, fell over spectacularly when it decided it could not operate in my locale nor use the gnome frontend to Debconf mid-way through the upgrade. Maybe that's my fault for running it in synaptic; but that's what the first page I found on the 'net suggested, and if they don't document the right proceedure, then it's still their problem.