Aerial Ace! I like how its attack never misses.
It's a very good move, my Lv100 Altaria still has it. :D
Two of my favorite attacks from the 3rd generation were, Luster Purge and Mist Ball that the Duo dragons had. They looked cool and were pretty good to use, considering LP lowers your SP.Def, while MB lowers your SP. Atk.