I think that my absolute favorite pokemon is (right now anyway) Drifblim, though I could go on and on. Also, Slowbro/Slowking are both reallly close right now.
One of my favorite teams is my Togekiss/Drifblim buffer combo. I have Drifblim stockpile and then baton pass over to Togekiss, who (with Serene Grace) boosts the rest of its stats, before using another baton pass to bring in a sweeper (usually Electivire). Works terrifically in double battles.