RE:
Well, I love threm all and I can't choose
Here why :
VOCALOID = The origin (so nostalgia) + most unique voices ever <3 And they're amongst my biggest favourite Vocaloids ever (Especially Léon, KAITO and MEIKO)
VOCALOID2 = I kinda "grown up" faster with these as I discovered it before discovering the V1 + some unique voices as well + TONIO. And Lily. Best reasons.
VOCALOID3 = smoothness, languages and Galaco bby <3 Without mentioning the first Vocaloids I4ve used were V3 (Galaco!Prize + MAIKA Trial)
So yeah, it's kinda like when I'm asked about UTAU VS VOCALOID I love all because the'yre complementary and each has something the other doesn't and vice-versa and it's just great <3
[Like, without the V1, no VOCALOID at all or not any generation after it and of course, being the first version it has some flaws. VOCALOID3 is HQ and opened the gate to more languages andsuch, yet some of the voices seems to have hard time to be energetic and peaky/clear... Not that it's not the case for the other verisons of the engine, but I think it was more noticeable (after we jsut have to find a great tuner and this problem gets away) and then VOCALOID2 got most of my favourite Vocaloids but at the same time well... ]