I can’t judge all of Linux, but I’m an Ubuntu user, so I can judge Ubuntu.
Pros: Free, easy to install, much room for tweaking to suit your preferences, pleasant to work with, quite fancy-looking, no viruses for it, generally quite stable, offers the possibility to work with the kernel directly via the terminal if the interface doesn’t do what you want (or if you’re just a nerd).
Cons: Can’t run most programs made for Windows. Only runs cross-platform (read: non-professional freeware) games, or gameboy and abandonware games via emulators.
I recommend dual boot; Windows for games and programs with no freeware alternative, Ubuntu for everything else.
Fun fact: After I installed my new motherboard, I have twice spent a whole day trying to install Windows XP on my computer. And it still doesn’t work.
By contrast, I could toss Ubuntu off my system and have it installed and running again within the hour.