He doubted Sam, but believing in him wasn't the right thing to do

That was my point -- that Sam was doing the wrong thing, but on the surface it was understandable why he thought he was doing the right thing. Unless we're drawing a clear line at ever working with demons, which certainly isn't the case down the road.

It also depends on how you're defining "let down," I think. If you mean Dean letting Sam down about something that he wanted, that can be different than letting Sam down because he didn't do what was right.

I think that doing the right thing for Sam is to oppose the people who want to use him to bring Hell on earth, so arguing against that isn't letting him down in my books. It's not the same as disagreeing with someone--he had Sam's best interests at heart (as well as the planet's) and he was right to boot.

In terms of major disagreements between Sam & Dean: other than Lenore, have there been any cases where Sam was proven right and Dean proven wrong?

Lucifer and the cage (and not saying yes to Michael) is a biggie. But I'm sure there are smaller case-related ones, like him getting the hellhound instead.

Sam knew he'd have a hard time offing his own kid, and saved the day at the last moment (and also proved she did indeed need to killed).

I'm not convinced that Dean would have been unable to resolve that situation successfully on his own though. He seemed quite onboard with the necessity of putting his freakish daughter down afterwards, unlike Sam's weeks of petulant sniping over lovely, innocent brain-eating Amy.

Dean: I can’t do this alone.
Sam: Yes, you can.
Dean: Yeah, well... I don’t want to.

Ok, a conversation two cubes down included the word supernatural. I totally wanted to barge in on the conversation to see if they were talking SPN or not. I don't have any SPN stuff in my cube - just baseball related things.

Work has kept me from watching Supernatural Shake. Will have to remedy that when I get home.

Sara wants to watch it ... well, almost as often as I do. ::hangs head::

I'm not convinced that Dean would have been unable to resolve that situation successfully on his own though.

If Sam hadn't shown up, he would have shot her, yeah, but he at least realized how hard it was to do with someone he had a connection to. And Sam had a much deeper friendship with Amy than the ten minutes Dean knew his daughter.

Sam's "petukance" is cast in a different light by Dean's resistance to the idea of Sam being the one that cleans up after Benny if he goes off the wagon.