They all were good but Weir is easily my favorite.

For the Leader, I think Woolsey was the best, while Weir was a good diplomat I don't think she did the best as the Leader of the Expedition, she just had the advantage of being able to pull some strings to keep the job after the siege.

My favorite as an Atlantis leader is probably Dr Weir. Although I did like that they stopped demonizing Woolsey and we got to see another side of him.