Vocaloids I like

Gumi


IA (maybe)


Meiko (She's a little choppy, though.)


Kamui Gakupo (You will never guess who provided his voice.)


Lily (maybe)


Utatane Piko (She sounded moe in the first song I tried, and now...what? Can they all do this?!)


Yuzuki Yukari


Tone Rion (I don't know why I like her. Maybe I'll change my mind later.)


List of others I listened to (in case I missed any)
Kaito
Leon
Lola
Miriam
Hatsune Miku
Kagamine Rin/Len
Megurine Luka
SF-A2 miki
Sweet Ann
Oliver
CUL
Ring Suzune
Aoki Lapis
SeeU*

*I didn't listen to her, but I read that she was Korean, so I wouldn't be able to use her.