It really depends on several factors:
If I know I'm going to lose then I'll resign, out of respect for my opponent's time.
If I'm in a losing position, then I'll play on until there's no reasonable chance I can get back into the game. When that position is reached, that really depends on my opponent. If my opponent is a lot stronger than me and played a dominant game, then I'll usually resign if I can't get any counterplay going. If my opponent is weaker and has blundered in the game, I'll play on, hoping to exploit weak endgame skills to my advantage. Also, there has been the rare case where I've been losing badly, but my opponent is in time trouble, and I'll try to exploit that as well.
To answer, it all depends.
do you guys prefer to resign when you know that you're losing or would you rather to stay in the game and prove that your the man even though you know that your going to lose..??