Both, really

BY FAR. It's the only time I cared for him. I actually love young John, despise older John.

Before he became an "obsessed bastard" (as Dean put it).

^^^ That.

And no one will convince me that he never physically abused Dean, in addition to the emotional abuse.

By a lot!

NCISLuverjk93 - doesn't the end of Nightmare contradict that idea, when Sam says they'd been lucky in comparison to Max?

I just think that it wasn't constant& he never broke bones or anything like that. Also Sam probably wasn't even aware of it. For instance in Dark Side of the Moon, when Dean finds out that one of Sam's best memories is the time he ran away& Dean was freaking out because he couldn't find him, the look on Dean's face when he said "And when dad got home..", it just solidified the idea for me. His expression was one of those who have been physically abused. Just my own opinion.

I don't like John much but definitely the younger John the most

Both.