So, without further ado - here are, in my opinion, and in order of season...
The 5 Worst Episodes of Supernatural:
1. Swap Meat
2. Manniquin 3: The Reckoning
3. Season Seven, Time for a Wedding
4. Man's Best Friend with Benefits
5. Dog Dean Afternoon
Honourable Mention: Bloodlines (This only gets honourable mention, because it's really an episode of a crappy other show that never happened.)
And, equally fun, and because for every bad thing I say about the show on here, I have to say one good thing. Here are...
My Favourite Episodes from each season so far:
2. Born Under a Bad Sign
3. Mystery Spot
4. On The Head of a Pin
5. Swan Song
6. The Man Who Knew Too Much
7. Death's Door
9. Alex Annie Alexis Ann
10. The Executioner's Song
If you're wondering why I picked "Home" as my favourite S1 episode, it's because that one was the episode that hooked me. That was the one where I became INVESTED in the show, rather than just watching it because my sister wanted to.
And yes, it was hard to pick between Mystery Spot and A Very Supernatural Christmas.
My favourite episode of all time remains On The Head of a Pin, super dark and depressing though it is, it's just far too gorgeous an episode not to love above all others. Not to mention that it has probably the clearest and best stated world view of the show summed up in a two line exchange:
"There is no Will. No Wrath. No God."
"Maybe. maybe not, but there's still me."
Mystery Spot, TMWKTM, and Sacrifice, are all pretty Sam centric episodes... or, I like them for Sam centric reasons. But, I see BUABS, Swan Song, and The Executioner's Song, as being Dean centric... or, I like them for Dean centric reasons. Then Death's Door, and Alex Annie Alexis Ann, I see as being excellent for showcasing the amazing supporting actors that Supernatural has, and how the show is able to populate it's world with really rich characters that could be the stars of their own shows easily.
Anyway, fun times... carry on as you were. I'll try to do another rewatch this weekend. :)