Although I use mostly Windows and Microsoft products at work (software development for huge non-profit place), I like Linux and the free software and open source idea, especially as for-profit software companies move toward time-limited licensing. I played with Red Hat 4 and 5 (when it was free) many years ago as a dual boot with Windows 98.
Recently I decided to give a few distros a try on an old Pentium II 400 MHz with 96 MB RAM and an 8 GB hard drive. Damn Small Linux (DSL) and Puppy Linux seemed like good options given this hardware, but I decided to see if I could get a full-weight distro working. The latest openSUSE (11) wouldn't run from a LiveCD, and an installation was more work since this machine was netless and openSUSE dropped install CD's in favor of a DVD's only. (The old DVD drive didn't support any of the DVD's I burned myself. I know I could've swapped a new one in temporarily, but meh.)
Next, I tried Ubuntu (with GNOME). GNOME was slow, and couldn't open some things due to low memory. I then downloaded the Xubuntu CD image and replaced GNOME with Xfce (without reinstalling the OS). (Xubuntu is just Ubuntu with Xfce installed by default.) This works much better, although it's still annoyingly slow on this ancient hardware. I also grabbed the Edubuntu iso for the kids, although we've yet to play with it.