I have to admit, when I had heard the episode synopsis for this episode, I got pretty leery.  Maybe because I'm still shaking off the hee-bee-gee-bees after reading RPF fan fiction involving Supernatural's three good looking leads.  How was that going to work in an actual episode, even if it was an alternative universe plot?  Luckily, Mr. Edlund drew the straw for this script assignment.  Whew, crisis adverted.  
Now, I wouldn't call "The French Mistake" the most brilliant episode ever, but hey, in a time where we needed something light, our show delivered big.  The inside jokes alone will keep fans entertained for decades!  Not since "Hollywood Babylon" has Edlund had the opportunity to take on one of his favorite targets, the Hollywood starlet mentality.  So what happens when Jared and Jensen are actually prima donnas?  Trailers come with remote control helicopters and large fish tanks and the luxurious mansions prominently feature Warhols of its occupants?  I tell you what happens, Sam and Dean acting like they've won the lottery.  
Somehow, in the midst of this total madness, an actual plot exists, even if it is somewhat obscured.  Let's follow the bouncing ball.  Balthazar arrives with a bunch of awesome Godfather references, which implies everyone is in deep doo doo.  With one swipe of the hand, Sam and Dean go flying into the alternate universe.  How many windows did they crash through in this episode BTW?  TPTB were certainly keeping Jared and Jensen's stunt doubles busy.   
Lucky for Sam and Dean, this universe is vacant is sooo many ways, including spiritual entities.  That puts them on an even playing field with the pursuing angel assassin and they take great joy in for once being able to kick angel butt.  They manage to get pulled back by Raphaella through the one portal that works and...guess what?  It was all a setup so Castiel could get the weapons back from Balthazar.  Who's suddenly loyal again.  Who still has a little vendetta for that frying wings extra crispy thing.  Castiel approved the plan and...still won't say why defeating Raphael is important.  Quite frankly, considering the vast amount of favors Sam and Dean owe Cass, the decoy thing was cruel, but forgivable.  I hope they get the message about what happens when you push your luck with angels.  
In this entire screwball scenario though, there's a chance to get philosophical. It's interesting to see them in a universe where all the evil they face is gone. No demons, no angels, no ghosts, no God either. The only obstacle is the self absorption of the people themselves. With no higher power, reflections and importance turns inward. Sure Sam and Dean don't belong in that world but would their lives ultimately been better with that life? Especially when luck for once turned in their favor? It's my guess it would have gotten old after a while for their sense of purpose would be lost. Still, a few more weeks in that life wouldn't have hurt. If anyone's earned an extended vacation, it's these guys. 

As with all Edlund scripts, the humor goes dark.  Very dark.  I remember laughing all the way through "Bad Day At Black Rock" until Bela shot Sam.  Fun over.  In this episode for me, it was killing Misha.  Aww, poor cutie pie in the goofy sweater.  Couldn't Virgil just have kicked him in the butt and sent him scampering instead?  Kripke I didn't mind though.  He's always wanted to do a Western and you can't go more The Good, The Bad and The Ugly inspired than that brutal end.  

Somehow though, in writing this review, I kept going back to "The Simpsons."  Remember the episode when Bart Simpson in his medicated haze figured out Major League Baseball was spying on Springfield?   Those two of you that do know, Mark McQwire shows up to do damage control.  I know, where am I going with this?  "Do you want to know the terrifying truth, or do you want to see me hit some dingers?"  "Dingers!" everyone yells.  
Here we go.  Instead of an in-depth review, I'm giving you all the dingers.  Batter up!

"You did, twice.  Good for you." 

Sam:  Should we be killing anybody?
Dean:  I don't think so.
Sam:  Running?
Dean:  Where?  

Producer:  We'd have to blow off the scene where they sit on the Impala and talk about their feelings.
Bob Singer:  Right, you answer the hate mail. 

"I'm a painted whore."

"Oh, if can you include the question in your answer."

Dean:  Why would anybody want to watch our lives?
Sam:  Well according to the interviewer not very many people do.  

Sam:  I'm just saying we've landed some dimension where your Jensen Ackles and I'm someone called a Jared Padalecki.
Dean:  Oh so what now you're polish?

"Like bizzaro earth.  But instead of getting bizzaro Superman we get this clown factory."

"Misha?  Jensen?  What's up with the names around here?"  

"Ola Mishamigos, J squared got me good.  Really starting to feel like one of the guys."

"That's fake me.  This must be fake mine."  

"Well he's not a hunter, but he plays one on TV."

"We're not even in America"

"Nice modest digs Jay Z."

Sam:  Wow, I must be the star of this thing.
Dean:  Yeah right.