I have been using Linux for over 10 years by now (was forced to install it on the second year at University), and after having tested over 100 distros/versions through time, Ubuntu is the friendliest one. I have been using it fulltime for 5 years now (since 5.04, previously I had dual booting), and the only one that came close was the old Mandrake (I ended up choosing Ubuntu because it detected and configured my sound card whereas Mandrake couldn't do it, even though visually was more appealing with KDE).
All Linux distros have wireless problems due lack of open source drivers, so if you are on notebook or use wireless, better to stick with Windows unless you want to tinker around. And the lack of games and friendly media editing tools is visible, so if you are needing those, you should probably stay in Windows. Dual booting is nice to test it if you are a newbie, but after a while, you need to choose whether switch over or remove it from your system.
Sometimes thing break under Ubuntu, I won't deny. For example, to upgrade to 9.10 I had to reboot twice since the first time most applications crashed when opened. But I have tried upgrading others (Fedora, I am looking at you) that mess all your system with broken dependencies everywhere, so much I had to fully reinstall. And unless you are a developer, Debian isn't useful (update cycles are extremely slow, usually year and half or higher). Unless you want to be Gentoo-ish and download the packages yourself, trying to keep your system up to date but hoping not to break dependencies when replacing libraries, don't use it.
Back when I installed my first Linux (Slackware 2 if I recall correctly) I had to use xf86config and manually set my monitor's vertical and horizontal refresh
Linux advanced a lot, but there are still visible problems.
