Sungha Jung. 

For those who have no idea who Sungha Jung is; he is a South Korean fingerstyle guitarist. He started his career with posting videos of him playing covers of songs he re-composed by himself on youtube since he was at a young age. These are some of the best covers he have done;

Maroon 5 fans:

http://www.youtube.com/watch?v=peWeqWUF--s&index=2&list=PLbgYjDW2chgt-xdkCuJvxz-o_WWL2vNeZ

http://www.youtube.com/watch?v=_I57GlmBzv0&list=PLE087FE590A48F20A

For those who are a fan of 'Frozen':

http://www.youtube.com/watch?v=AAnID4RS7Vg&list=PLbgYjDW2chgt-xdkCuJvxz-o_WWL2vNeZ 

And my personal favorite:

http://www.youtube.com/watch?v=AY7W-hLXO_M&list=PLE087FE590A48F20A&index=4 (Nirvana cover)