Seeing how one of the first games I ever played on the computer was Wolfenstein 3D, I'm going to say PC. I also feel like PC gaming is for everyone, and not just some hardcore gamer. The only hardcore aspect of gaming on PC would be the hardware enthusiast, which I am not.
I tend to discredit the excuse, "I don't think I can use a mouse and keyboard." Anyone can use a mouse and keyboard, if you can write your name fluently then you most definitely have the dexterity to play on PC. Especially nowadays with the technology in keyboards and mice. All you need is a decent keyboard, and a nice mouse, preferably optical and you'll be good in no time. Like everything in life, it takes practice and the more time you dedicate to practice the better you'll get. Eventually you'll have the muscle memory to do flicks, 180 snaps, and other things that you might have thought hard to do.
I'll leave the obvious and clear advantages of PC gaming out. Most people should know them, especially if you're in school and you've done some word processing before.