(Sorry if this is off-topic )
I really enjoy pretty much all of the Piano Guys songs (sorry, but Let It Go does not make the cut).
They do a lot of instrumental remixes of popular songs (I.E. Let It Go, Rolling in the Deep, Etc.), but they also have original songs, too.
Here's some of my favorite Piano Guys Songs (no particular order):
- Code Name Vivaldi
- Arwen's Vigil
- The Pirates of the Caribbean one (I don't remember the exact title)
- The LOTR/Hobbit one (Again, don't remember the name)
- Michael Meets Mozart