I would say I have had somewhat few perfect 10 teas but some notable favorites include:
Sencha: O-cha 7132, Ippodo's Hosen.
Gyokuro: Yame and Kame from O-cha
Hong-Cha: Mandarins Tea Room Yixing Red and Jin Jun Mai, and Tea Gallery Keemun.
Korean: Dao Tea's Balhyocha, and quite a few different Korean Greens.
Highfire TGY: A sample I received from a forum member, and Mandarin tea room's Classic roast.