Those I4H 4/20 eps always blow my mind. On last years I considered not listening because I thought it would just be a mess but the weed seems to aid improv. I suppose I base that all on the one Doug Loves Movies where Benson got high and it was so terrible he disowned the episode.
I don't know if it's because these are all guys who can handle their weed, because they aren't doing it in front of an audience, because they are all such good friends and seasoned vets, or a combination of each that makes the 4/20 eps so damn good.
Edit: They have such a unique and faster beat to them than the other eps.
Edit2: Ahaha, And there is a great weed lapse from Seth Morris and Gemberling. I'm not high, I just love these eps.
Edit 3: Bikini Squad! Holy shit, fourth wall devastating. I love these eps. I am not high.