3) Kokoro we komete - Aoi Teshima: I use it to reference keys and levels for strings and guitar. The mix is so patient, gentle and nice.
4) Colbie Caillat - Goldmine: This is one of my most busy reference tracks. I actually started to use this, because I saw a walkthrough of the mix on Youtube, and discovered it helped me using it for reference knowing what was going on.
As you can see, I could use some more busy and drumheavy reference tracks.