My favorite would be VY2V3. He sounds AMAZING! I wish I could have him! And I also LOVE Gakupo's extends, as well as MEW and CUL. I am REALLY looking forward to Mayu
Now, who I dislike the most is SeeU. I think they could have worked harder in her design (I like her hair though) and I like the Korean Vocaloid concept, but...her voice didn't convince me.
Another one I don't like is Aoki Lapis. Well...I like her, but I dislike her. Her design is just beautiful, but sometimes I find her voice annoying, while other times I find it perfect.
Soooo...yeah~