All the pants need to be redesigned to stay up.
I agree that the leotard look is a bit strange. It makes Joe look like he is dancing back there when he is under pressure (and it is not Swan Lake).
The uniforms that I dislike the most from a purely esthetic view are the Titans and the Raiders. The next tier of dislikes would be the Bills, Broncos, and the Jets.
Then there are the "throw back" (throw out?) uniforms in general - a blatant money grab for the teams, and I imagine a hindrance for some QB's in finding their receivers down field. And, yes, Pittsburgh's are the worst of this bunch.