I've been running Ubuntu Linux as the primary OS on my laptop for about a year and a half now. The current release, Ubuntu 8.10 (Intrepid Ibex) was fantastically easy to install: it completely walked me through the installation, and I didn't have to hunt around for any drivers at all. It recognized and configured all the hardware in my HP nw8240, including the built in wireless and the built in media card reader, without any work on my part. It was also fantasticly easy to use after installation... Firefox was installed as the default browser, and OpenOffice.org was the default office suite. In general, I've been very happy with it, and excited that Linux development has progressed as far as it has. I would totally recommend Ubuntu to the average Joe who basically uses their computer for email, web browsing, and office work. I especially think it's suited well for the surge of netbooks that is hitting the market.
Now that I'm moving in with Aaron, though, I've been looking for ways to to reduce the amount of clutter in my life. One of the things that will probably be going is my desktop PC; I'll be using my laptop as my main computer. And I'm sorry to say, there are too many things that Linux still has a hard time with to keep it as my laptop's OS.
My hugest disappointment is that there isn't a port of IrfanView for Linux, or even a very good replacement. I've been using IrfanView since its first release, and it is by far the best program out there for viewing and doing simple modifications to graphics files. GThumb was the best replacement I could find, but it's not nearly as fast, and the interface is much clunkier.
Second on the list was compatibility between OpenOffice.org and Microsoft Office. I found OOO to be a great, fully-featured office suite, and I think it would be a good replacement for MS Office if everyone was using it. Most people are still using MS Office, however, and while the OOO suite is able to open MS Office files, I found that the conversion was somewhat lacking.
So, I've spent the last couple days installing Windows XP and all my regular Windows apps, and getting everything configured the way I like it. I'm looking forward to the day that I can go back to Ubuntu and say goodbye to Microsoft for good, but that day isn't here yet.