I use Ubuntu. I like it much more than Windows.
The only problem I have with it (and it's not really even Linux's fault), is that for most ACPI functions of hardware, the developers use sloppy standards to comply with Microsoft's sloppy APIs. As a result of sloppy development and Linux's tight standards, I need to hack my kernel to pieces to get Ubuntu to recognise my laptop battery/temperature/voltage/etc.

I keep a Windows partition for games like Oblivion, but that doesn't mean I want to.