Let's forget physical instruments.
Play Guitar! is a great app by Davilovick. Playing a guitar in real life is quite difficult. Pressing the strings on one side and strumming on the other can get quite difficult. Not everyone's a Jimi Hendrix over here now. I myself used to learn how to play the guitar, it was never easy for me too. I have really soft fingers, and it hurts me a lot in the fingers. Play Guitar! makes it effortless.
Play Guitar! can be used on a Windows 8 tablet with the touch-screen or a Windows 8 computer using the mouse, though overall the experience is much better with a touch-screen.
You are greeted by a classic acoustic guitar with intricate designs. From the guitar to the strumming, everything looks life-like.
You can add chords: Major, Minor or 7th to your list. If you want to play a song dragging the chords required to the list makes it easy to access them, without any mess.
If you do not feel like playing any chords you can switch to the free play mode. Play Guitar! however lacks an electric guitar mode right now. That would have been a neat addition and would have pumped up the ratings.
Play Guitar! is one of the best guitar apps on Windows 8. If you have a touch-screen, it makes it better for you.