I'd have to say the majority of the taunts from SFIII:TS are great. Chun-Li's yawning and stretching, Makoto's flexing, Yun's twirling hat, Elena's handstand, Dudley's flower toss, and so on (and of course, the fact that they alter a characteristic by completing one means there's actually a purpose to them aside form just showing off).
For intros, I love ones that apply to the characters and connections between them. KoF has plenty of these, though I don't play it enough to really know any in particular. Alex/Hugo in SFIII:TS is great, as is Kyo/Ryu in CvS:MotM.
Might I also add almost anything by Lillith. Her wing-turned-hand gesturing a finger for you to "come on", her sitting down clutching her stomach while thinking of food, and (even though this is off-topic) her Showtime! super (one of the Greatest. Supers. Ever.).
