Me personally, Psychic, Dark, Fire, Ghost, in that order. I always pick the fire starter, and try getting a abra asap, since the original game. I like fighting too but every time I tried using one it turned to a massive failure.
I absolutely detest bug and normal pokemon, and have NEVER used them for any reason besides necessity, quickly switching them out asap. Ground and Rock pokemon I don't like either but I have willingly used them, and willingly keep them for awhile.
Sadly though it seems that the dark and ghost pokemon i've tried using were usually unable to keep up with just normal battling without the aid of others.