Linux. I was a Windows guy but from last two years I'm using Ubuntu. I don't have any driver issues and everything works quite well. In fact, it works better than Windows 7 for me. I'm primarily a developer and it is well known that Linux is best for that purpose. I am also a part time designer and GIMP/InkScape works well for most of my needs.
I still have Windows 7 installed, but I only use it(occasionally) if I need to work on things like .net, photoshop, illustrator etc.
I still have Windows 7 installed, but I only use it(occasionally) if I need to work on things like .net, photoshop, illustrator etc.