Here's a ranking!
It's up to date as of Elednist's post.
Top 16 songs (so like if you wanted to make a CD) based on weighted score (If your post says "In no particular order," they all got three points so they had the same weight).
1. M (28)
2. Memorial address (25)
3. Love song (24)
4. SURREAL (23)
5. A Song for XX (17)
6. JEWEL (15)
7. Last angel (15)
8. evolution (13)
9. Terminal (12)
10. alterna (11)
11. NEXT LEVEL (11)
12. RAINBOW (11)
13. 1 LOVE (10)
14. HEAVEN (9)
15. walking proud (9)
16. Will (9)
The top 5 based solely on number of times mentioned:
1. M (8)
2. Love song (8)
3. SURREAL (7)
4. Memorial address (7)
5. Last angel (5)