I think Starmie is becoming a favorite of mine (not sure why it wasn't sooner). I don't think I could confidently say that it's my favoritest favorite though. Eevee has a pretty strong position in that regard. But Starmie does get bonus points for being, y'know, a star. Two stars, for that matter.
EDIT: Actually, I nearly made myself a Starmie PokePet a month or so ago after following the link above Will's Amor. >_>