Linux is perfectly fine for GUI users. It's really great for most common use cases. You might have issues with games (or so do I've heard), but I'm not a gamer and don't know much about this... Steam has helped make games on Linux a lot better. I just play supertux or supertuxcart or mahjong once in a blue moon and am happy.
Most things work perfectly - stick to Ubuntu or Fedora or opensuse. Once you get the hang of things, things actually feel better on the Linux desktop:
much faster than Windows
no tracking
highly customizable
if you ever get into it, you can script your setup to be easily replicable across machines
Things that you'll have to fight
fingerprint scanners - only a small subset work. My Dell latitude scanner works perfectly though.
some printers might need manual driver download/install
some software is only built for Windows (less and less of those these days, unless you're doing something specialized)
