I fucking ADORED that episode. I cried (real tears!) for the first time in ages. I realise that's because I am Sam sympathetic (I've decided not to call myself a Sam!girl because I fucking adore Dean too, but I DO sympathise with Sam massively) and that episode spoke to me on levels I can't render into words at the moment.
I have so much I want to say about that ep (about Dean's characterisation, Sam's headspace, Sully and other important stuff) but I can't at the moment. But I will - at some point.
In short - great acting, directing and script. So much heart and soul poured into it all.