Well, I have tried three types Vocaloid2
1. 01 - Hatsune Miku - She have specially beautiful teenager voice XD.
2. 02 - Kagamine Len\Kagamine Ren - Both of them are special, one with relaxed boy voice and another one with cute-moe girl voice.
3. 03 - Luka Megurine - This newcomer has surprising beautiful mature voice XD.
For me, I chose Luka, since I like a bit more matured voice XD