It is very easy pointing out BAD directoers.
That's sort of the point, though, innit? A top ten of the worst directors would take forever just to get the short list.
It's just a rule of the entertainment--people like complaining more than they like appreciating good work, and a certain class of person
hates to admit to enjoying something unless there's some sort of evidence or style guide they can cite for why it's okay to like it.
Anyway, my favorite directors are mostly bad directors. Their movies might be totally flawed, but there's so much humanity in the stuff--you can really see those directors in the flaws. I guess it's like the whole "gesture of the artist" thing that they like to talk about in art history classes. So anyway, in no particular order I like Tarantino and Kevin Smith and Joss Whedon and Aaron Sorkin and Charlie Kaufman.
Or to give a separate list that I probably like just as much: Gendy Tartakovsky, Paul Dini, Giancarlo Volpe, Kazuya Tsurumaki, and Watanabe Shinichi.