Mine would be in no particular order:
Arirang - tied with Ddaeng and Daechwita. Always love the mix of traditional instruments into modern beats. Also, with Arirang, love to hear vocal line's lower registers.
Dead leaves - same reason with Arirang.
Paldogangsan - coming from a province, I love a track that uses a dialect and also I can compare the structure of the song with some literary forms in my own culture. I don't understand Korean that much but I love how satoori sounds.
Still with you - Jazz
First Love - just how the emotions wrung out of you through the instrumentation and the way he raps that it forms a story. From how it starts almost bare with instruments then the piano and the strings pile up into a climax then halts.
Scenery - the dreamy, innocent and nostalgic feel of it all.
Outro:Tear - just the intensity. The intro melody gets me every time.
Lie - the drama of it all. The intro.
Spring Day - Queen! Something close to my ballad tastes.
