I am using Debian on my machine. Â Debian comes in 3 flavors, actually 4, with Old stable (currently called Etch). Â Mainstream one is Stable, currently named Lenny. Â Lenny was released about a year and a half or so ago, it is current with security updates. Â Software can be a bit dated by now, but it works well. Â "Testing" is the next version that will eventually be released as "stable" probably later this year. Â It has mostly current software. Â Current Testing version is named "Squeeze".
Experimental is the bleeding edge version, sometimes things 'break'. Â Experimental is always named "sid"
When Debian releases Squeeze as "Stable" later this year, "Lenny will become the Old stable version, and a new version for Testing will start.
Ubuntu is based on Debian Experimental, so it is always more current, as well as having a faster release cycle, something on the order of 6 months.
Most of my equipment is a bit older these days, light on ram, Ubuntu seems to run better with more ram. Â My Debian installs, with current releases, have been happy with lighter ram that I have, so far, than the equivalent Ubuntu current releases, which have always seemed a bit sluggish for me.
Ubuntu does a lot of focus on making things work, so if you are unfamiliar with things 'under the hood' it is more likely to work for you. Â Tips and tricks published to get things working for ubuntu, almost always are good for debian, due to the common structure.
I'm playing with Puppy as well, but as my base debian install is working well, I just don't mess with it enough to get more comfortable. It's actually what I keep on an older machine I have, but again, I don't use it that much these days. The eee is just too handy and at hand all the time.
Both Debian and Ubuntu default with Gnome, I've been more comfortable with KDE personally. Â Both make it available easily
There is a current release of knoppix, 6.2 which works pretty well for me, at this time. Â Also based on Debian, with a light weight windows manager.
Linux Mint, also a debian/ubuntu based distro, is also rather popular.
I replaced the stock xandros OS that came my eee with a full debian "Lenny" (debian eee project) install on my little Asus eee and it is running quite well for me, no complaints.
Just wanted to add a bit of background for consideration to the thread. Many of the perceived shortcomings of another distro are probably me just not being familiar with it.
Underhill