I enjoy both factions a great deal. I like the characters on all sides, yes even Trade Prince Gallywix, Nathanos and Sylvanas. Everyone brings something to the table to make a fairly good story in game. I even like the bad guys in some cases, like the two headed Ogre, some of the Legion bad guy cast and other expansion.
Special note to Gul’dan. About the only bad guy\character I enjoyed disliking. It was the first time I specifically went into a raid to kill something with intent. Blizzard did a bang up job painting him as truly really a bad guy. Maybe it was seeing the movie or they a lot of time to develop. My hat is off to Gul’dan, may he rest in torment.