Linux is the Way and the Light where PC's are concerned. Everything Jude said about it is true. The only things I would add are:
1. There's a lot of different interfaces rolling around, and they're all customizible. Look at a few different Disributions and find one that looks good and workable for you. (I use a customized version of Xubuntu, which uses a lighter interface than the graphics - heavy Unity, or certain others.)
2. People occasionally have driver issues with certain graphics cards and wireless cards (Broadcom Wireless is a good example...), so I'd advise running the Live CD first, or doing a dual boot initially just to give yourself familiarization time, and to poke around and make sure every last little thing works.
There's a very helpful community out there, help usually gets posted quick on the forums, and there's a fix out there for most anything that goes wrong. The vast majority of machines seem to work with little to no tweaking, and the more front - running Linux Distros like Ubuntu and its variants are very new-user friendly.
Good luck and have fun!
...They Don't think it be like it is, but it do.