Third time's the charm, they say. Since the previous Comedy Episodes ("Monster Movie" and "Yellow Fever") offered good laughs at the cost of great plotting and pacing, this one finally delivers also on those areas. It is also, arguably, the funniest of the three. And, after an intense Mytharc Episode, a *great* Comedy One offers nice balance to the series.
From the get-go, this keeps on coming up with great moments - clever, witty, surprising, or all at once - at a crucially consistent frequency (unlike in "Monster Movie"), and, equally importantly, it is all played with a straight face: this *is* a legitimate case for the Winchesters - they are as caught off-guard as the audience by the insanity of it all, but they never forget that the supernatural forces they keep facing are almost always dangerous and must be faced with caution. The guest characters involved in the story feel very human with their ordinary lives and problems. And when the story concludes, it has affected all of them and hopefully left the audience appreciating what is good in their lives.
Also, this episode occurs firmly within the Mytharc, unlike "Monster Movie" and "Yellow Fever", which could *almost* as well have been stand-alone episodes in some other season. No, the Mytharc is present here, even if - as we can see from the opening credits - Misha Collins and Genevieve Cortese aren't. The script gives the best bits to Jensen Ackles, and he is on top form throughout, especially when struggling with his metaphorical demons.
Conclusion: effortless greatness, 8/10, but not Classic or truly Exceptional.