IA story sucks, i already made a thread about it, too lazy to make another
companion/story for IA sucks(lvl 50 IA)
BH on the other hand, has awsome story/companion.(IA feels very sloppy in comparison)
I hear JK story is awsome, gonna do that next.
It's cliche but it does turn you into the top 10 most powerful jedi of all time.
As for OP
Best: Knight/Consular (simply because the enemies you beat are byfar the strongest enemies compared to other class boss and awesome companions)
Worst: Smuggler. Although I did enjoy the smuggler story very much, you just feel like an errand boy. Same goes to the IA (along with its terrible companions).