You must have really weird software. OS X, Linux (and BSD), and Windows all suck in different ways. One way that they all don't suck is out-of-the-box hardware support, all three OSes support most common hardware just fine. I run Debian Unstable and I don't think I've ever explicitly installed a driver, everything is in the default install. (I think Intel is mostly to thank for this situation on Linux; Intel has written great wireless and video drivers, so if you have Intel hardware, everything is likely to work really well.)

So if hardware is not a problem, it comes down to the software. Everyone uses the same web browser on all three platforms, so it's not that. Linux has better terminal editors and support for programming. (I ditched OS X after never getting emacs to work right.) Nautilus and Finder are about the same, although I do not like to use a GUI for managing files. Linux lets me choose, OS X forces its opinion on me. (I also don't like manually arranging windows; OS X forces me to do that anyway. It doesn't even have working "maximize".)

Anyway, I spend maybe an hour every two weeks caring for and feeding Debian, and that means all my software is always up to date. On my OS X machine, I spend less than that, but every piece of software I have is outdated since it is too annoying to manually update everything.

YMMV, but Ubuntu is probably a fine OS for 90% of computer users (especially with OO.org 3).