I don't really listen to Vocaloid lately, it's mostly GARNiDELiA on repeat nowadays (Goodbye Miume...), but I'd say
10. I think I Just Died [Guiano]
9. Dance of Reality [ATOLS]
7. Superhero [Guiano]
6. Tie between the Two Breaths Walking trilogy, Streaming Heart and Delusion Tax [DECO*27]
5. 4BLOOD [KIRA]
4. Scattered Glass [cillia]
3. Cendrillon, the 10th anniversary version [DiosP]
2. Tie between Henceforth and Asu no Yozora Shoukaihan [Orangestar]
1. Hana [Guiano]