Here's a top ten list that's been on my to do list for some time.  As you all know, Supernatural episodes are divided between mytharc episodes and stand alones.  I've never taken a look at the stellar stand alone episodes that have given fans some extraodinary memories from the series.  

What is a "stand alone episode" exactly?  I thought I had an idea, but Supernatural always likes pushing those boundaries when it comes to its episodes.  A lot of the MOTW (monster of the week) episodes have some sort of tie in to the mytharc.  So, I went to Google and found this definition: 

An episode that can stand alone on its own with a self-contained story that does not need prior viewing of any other episode to understand. It's usually an episode that breaks from the current arc to focus on a one-shot subplot or character.  
Okay, good to know.  The question I've asked myself for every single episode on this list, "Could a new viewer watch this episode and not be confused?"  I think all of these meet that criteria.  Once I started listing and ranking qualifying episodes, the results surprised me a little.    
By default, almost all of season four was eliminated.  Almost all those episodes were part of the mytharc in some way.  Also, by season seven, there's always some sort of tie-in, so for some episodes the rules were loosened.  Not too much though, just enough for a person not to be confused, but knowing the history might change one or two of the scenes for them.    
Once I came up with a list based on that definition, I ranked the episodes not only by gauging fan delight, but also those that make my re-watch list constantly.  You know, the "go to" comfort episodes.  A few that made this list are under the radar episodes that fans would never consider to be iconic, but as a standalone they're actually quite good.  Not surprisingly, several are comedy episodes.  Yep, more than half the episodes on this list were written by Ben Edlund.  
Another surprise that I found, not a single season one episode made this list, even though most of that season was stand alone episodes.  The problem is, my favorites from that season were all the mytharc ones.  The others just didn't stand out like the other episodes on this list.  
Okay, since the selection criteria has been spelled out, here are the top ten (with an Honorable Mention) Supernatural stand alone episodes.  Up first, part one, aka an Honorable Mention and episodes 7-10.  

Honorable Mention - Ghostfacers

Season:  Three

Why it's on the list:  I know that the Ghostfacers are an acquired taste, but the sheer inventiveness of this episode cannot be denied.  Considering almost all of the episode was shot reality style on shaky hand cams, it was just too precious.  Sam and Dean's cuss words being bleeped out, priceless!  I loved this one way more than the predecessor "Hell House," if anything because the whole inept Ghostfacer team was far more entertaining than just the two losers in a trailer in West Texas.  

Favorite Scene:  I gotta go with Harry talking a grief stricken Ed through his crucial task, getting the lost ghost of Corbett to move into the light.  "You've got to go be gay for that poor dead intern."  

10.  The Usual Suspects

Season:  Two

Why it's on the list:  This could be personal bias, but this is one of my all time favorite episodes.  I really don't know why, but the writing and dialogue through the entire episode was sharp, it was very entertaining from the first second and this is the first episode that showed Sam and Dean working totally together even though they were in separate locations the entire time.  I still snicker over both of them in separate rooms calling the same public defender "Matlock."  I loved Linda Blair as the cop Diana Ballard who ended up being far more open minded than her crooked partner/lover.  The MOTW story was really awesome as well.  
Favorite Scene:  Even though I drooled over almost every Sam moment in this episode, it was Dean's fake confession that struck me the most.  "My name is Dean Winchester. I'm an Aquarius. I enjoy sunsets, long walks on the beach, and frisky women. And I did not kill anyone. But I know who did. Or rather what did. Of course it can't be for sure, because our investigation was interrupted. But our working theory was that we're looking for some kind of vengeful spirit."


9.  Hollywood Babylon

Season:  Two

Why it's on the list:  This one almost got eliminated from the "standalone" criteria, because it's so thick with inside jokes.  Once I looked at the inside jokes though, a lot of them were making fun of Hollywood and pop culture in general.  For example, it's possible anyone seeing this show for the first time would crack up over Sam Winchester being bothered by the prospect of seeing Gilmore Girls cast members.  That was a very popular show and many would know Jared.  They probably also knew McG too and his stellar contributions of the Charlie's Angels movie series (ha!).  Ditto with the shallow demands from the studio suits who don't like that a horror movie is so dark and depressing, the writer who needed to add some "jazz" to the page, and that Dean Winchester really does make one hell of a PA.  I remember many critics adoring this episode even if they didn't get the stuff like why salt deters ghosts or why the weather was "practically Canadian."  The bottom line, the references and slams against the shallowness of Hollywood and the people there were so plentiful and so freaking funny it all sticks with you forever.
Favorite scene:  This is really hard for this episode, because every scene had a hidden reference or line that made it a must see.  I'll go though with the end, starting with Sam watching shooting of the newly written scene copying everything he and Dean did during their ghost encounter, Dean stumbling out of Tara Benchley's trailer very smitten while she declares he's "one hell of a PA", and Sam and Dean walking off together with the fake sunset as their backdrop.    

8.  The Curious Case of Dean Winchester

Season:  Five

Why it's on the list:  This is one of those under the radar episodes, much like "The Usual Suspects" that many don't list among the greats, but upon watching find it really enjoyable.  For me, it was all about Chad Everett.  I know, it's unpopular to have one of the two leads missing for more than half the episode, but you couldn't find anyone more brilliant to play Dean Winchester at 80 than Chad Everett.  He had everything about Dean down pat.  Couple that with Jim Beaver's irascible Bobby and it's Grumpy Old Men Redux.  In other words, a howling classic.
It isn't just Chad Everett though.  I loved the whole poker scene between Sam and the witch Patrick (Hal Ozsan).  The back and forth was intense and highly unpredictable.  No one could have possibly known that Sam was such a good bluffer, especially Bobby and Dean, who highly doubted him.  It certainly took Patrick by surprise.  Just from beginning to end, every bit of this episode was a treat.

Favorite scene:  The closing scene again.  After Sam leaves to take care of that little VD problem that Patrick gave him, restored Dean and recently handicapped Bobby have a heart to heart.  Dean makes it so clear how much Bobby means to him.  "You're not useless Bobby.  You don't stop being a soldier cause you got wounded in battle. No matter what shape you're in bottom line is you're family. I don't know if you noticed but me and Sam we don't have much left. I can't do this without you, I can't. So don't you dare think about checking out. I don't want to hear that again."  Oh man, where is that box of tissues? 

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7.  Bad Day at Black Rock

Season:  Three

Why it's on the list:  This is the first and one of the few screwball comedies done on this show.  This script is fast paced, ingenious considering that the foe was a cursed rabbit's foot, and the dialogue hilarious.  I laughed myself freaking silly.  A top notch episode all around.

It was quite shocking to see how brilliant Jared Padalecki is at physical comedy.  The amount of pratfalls and total physical harm he had to endure was, well, hilarious.  Who knew his big height could play to such an advantage.  No one though will forget pouty Sam, who's run of bad luck didn't stop with a broken sewer drain.  "I lost my shoe."  Jared sells himself way short when he says he's not a comical actor.  Watching Jensen enjoy Sam's and then his run of good fortune too was like watching a kid in a candy store.   Pure joy, especially when he got to take out the bad guys so easily.  "I'm Batman."  

Favorite scene:  I love the action scene after Sam and Dean enter Wayne and Grossman's apartment for the first time to retrieve the artifact they stole.  The choreography of the entire scene is physical comedy perfection.  Since Wayne has touched the rabbit's foot, everything is going his way, including easily stripping Dean of his gun and Sam and Dean both taking each other out by merely banging into one another.  When Sam is being choked, a desperate grab at the rabbit's foot changes everything.  Now the boys have all the freak accidents go their way, and Wayne and Grossman are taken out by weird happenstances, which end when Sam's gun flies right into his hand.  Dean asks, "Is that a rabbit's foot?"  Sam holds it up and looks.  "I think it is."  

Click here for part two!