My opinion (I only picked the songs I like most, cause kpop's ballad list could be very long)
(only groups, it doesn't include solos or sub-units, cause it would be too difficult to choose)
10. https://youtube.com/watch?v=nqaSboKBIuA
9. https://youtube.com/watch?v=blSCDrx0CDA
8. https://youtube.com/watch?v=LsmcZqWmx5I
7. https://youtube.com/watch?v=AG0jlKdB1s0
6. https://youtube.com/watch?v=0AFS803b06o
5. https://youtube.com/watch?v=H0eT9omRQS0
4. https://youtube.com/watch?v=gEqlF5N8UMs
3. https://youtube.com/watch?v=2GRP1rkE4O0
2. https://youtube.com/watch?v=5n4V3lGEyG4
1. https://youtube.com/watch?v=Mts3QqlMjYY
(only groups, it doesn't include solos or sub-units, cause it would be too difficult to choose)
10. https://youtube.com/watch?v=nqaSboKBIuA
9. https://youtube.com/watch?v=blSCDrx0CDA
8. https://youtube.com/watch?v=LsmcZqWmx5I
7. https://youtube.com/watch?v=AG0jlKdB1s0
6. https://youtube.com/watch?v=0AFS803b06o
5. https://youtube.com/watch?v=H0eT9omRQS0
4. https://youtube.com/watch?v=gEqlF5N8UMs
3. https://youtube.com/watch?v=2GRP1rkE4O0
2. https://youtube.com/watch?v=5n4V3lGEyG4
1. https://youtube.com/watch?v=Mts3QqlMjYY