It would really all depend on which Pokemon people ended up using. In particular, I found Elesa to be the easiest, because she used two Emolga, and I happened to have a Zebstrika on hand to waft away those pesky Double Teams she tended to like using. Not only that, it stopped her from Volt Switching on me, and all her Zebstrika could do to me was that Fire-type attack that boosts Speed, and while I was the same, I seemed to do more damage than her, anyway.
Speaking of, though... Burgh was a pretty easy Gym Leader, too; not only did I have Tranquill to take care of him, I also had my own Leavanny and a Drillbur.