Killing a helpless man stuck in a bear trap with a pitchfork? Not happening. The only thing that could've prompted me to go that psychotic was if they'd hurt Clementine. If that ever happens, all bets are off.
Left the other brother alive as well. The guy was already beaten and was no longer an immediate threat. You've got the entire group watching you and you're a convicted murderer. If the truth about Lee's past ever comes out (and it will), it'd likely set the group at ease knowing from experience you're not a coldblooded murderer, so I think its the smart play in the long run, too.
I basically feel like all of my actions revolve around the concept of "what's best for Clementine?" She represents the good that's left in the world and why it's worth saving. I'm not about to subject her to more horror through my actions.