Well, I can't believe you guys all missed the obvious winner: United.
Face it, United Stewardesses can beat any other stew with one hand tied behind their back. Heck, with BOTH hands tied behind their back. All the United girl has to do is sit on one of those itsy bitsy Singapore girls and that's it! Game over! The Singapore girl will be lucky to breathe again, let alone walk.
Yep, United. You know they have a weight limit for their stewardesses? That's right, each girl has to be a minimum of 200lbs or better. Occasionally they might let a 180lb girl in if she's got really, really big thighs or if she's really old and fugly. Oh yeah, United's the winner, no question.
Now however, who has the HOTEST safety video?? Gotta be Delta, my oh my oh my. I'd stopped watching the safety video 20 years ago, until I got on a recent Delta flight that is:
http://www.youtube.com/watch?v=MgpzUo_kbFY