(However, I think you should have removed the choices "Solaris" and "*BSD" and made the question "Favorite Linux distribution?" Debian, Red Hat, Gentoo, SUSE, Mandrake/Mandriva, and Slackware are all the same GNU/Linux operating system under the skin.)
Although I have long appreciated Un*x OS's and used and often enjoyed several free and commercial implementations, several years ago I became disenchanted with using a free distribution on my home PC because it seemed like I was putting all my recreation time and too much should-be-sleeping time into just getting the operating system set up the way I wanted and no time into doing anything actually useful or fun. (... OK, I confess, fiddling with the OS is at least a little fun for me. Hello, my name is papa and I'm a computerholic.)
However, Ubuntu has brought me back into the fold primarily because it is so much less work to install than any of the other distributions I've tried. It comes with a well-rounded suite of applications (OpenOffice is a great boon for Linux in general), has an attractive and intuitive GUI that handles basic operations (e.g. Network Manager works really nicely with my wireless LAN) without going over-the-top on special effects or visual clutter, performs well on old 2nd-hand hardware, and all PHENOMENAL! COSMIC! POWERS! of Un*x just a click and a terminal session away. (And, yes, those last two points are shared by most Un*x implementations.) Anyway, Ubuntu is easy to install, and the standard GUI has enough to get me through the days I don't feel like fiddling, but not too much that makes me feel like I'm in a 1970s "B" sci-fi movie.
(Yet another forum!
...)