Which of the 3 bosses was the worst?
I think most people will agree that Julia was definitely the lesser of 3 evils. So it comes down to whether it was Harken, the greedy, power-tripping sociopath, or Bobby, the hedonist who used his daddy's company as his own personal piggy bank.
I'd say that Harken was the most fun to hate of the 3, but Bobby was probably a little worse, since his irresponsibility and selfishness threatened the lives of thousands.