All of them Particular favorites, as of recent are Dark, Ghost, Psychic, Dragon, Ice, Water, Grass, Poison, Bug, Steel, and Flying. In other words 11/17, leaving out Rock, Ground, Normal, Fighting, Fire (irony because I'm obsessed with a certain Salamander), and Electric. ...Yeah, I'm pretty open-minded about most types :|b
Ghosts are underrated but can pack a punch.
Dark types are either very offensive or defensive. Plus they make Psychic types cry.
Psychic types are pretty damn powerful.
Dragon types are, well...dragons.
Ice types are pretty, and freezing can be pretty handy. Also they're the only types (save for abilities) not hurt by Hail.
Water types are graceful, and while overrated I must admit it's for good reason.
Grass types are cool and have access to quite a few status moves.
Poison types specialize in poison (obviously), and we all know how deadly that can be in the long run.
Bug types are also underrated but are so much better in reality.
Steel types are walls. 'Nuff said.
Flying types are graceful and have pretty decent moves and power.