As I said in the other thread, mine is:
June 15, 2010: The Legendary PAUL F TOMPKINS Is Live In The Studio Along With Puppet WALLY WACKIMAN And Tom's Protegee THE H-MAN! A Call From DAMIAN From F'ed Up. The Musical Pacings Of The West Wing Are Discussed And More! You Can't Miss This One!
I'm a fairly new FOT, and this is the show that got me to transition from just listening to the Gems podcast to downloading full episodes and listening live. Aside from a brief slow start, it's hilarious end to end. Milo's call about D&D, Tom and PFT's faux-interest in an epically boring Michael-K.-from-the-Cynics anecdote, Tom's "all fives" story about an unscrupulous car repairman, Tom razzing the H-Man about getting a job, a caller suggesting that Wally appear in corporate training videos, the West Wing music bit... there's more, too. Just amazing.
Not to be a copycat, but I too am a fairly new FOT and this was also the episode where it all finally clicked for me and I made the transition from Best Show Gems into the Best Show proper. I think the combination of Damien from F'ed Up, and PFT and Tom in studio, dealing (masterfully) with calls Milo, Spike, *and* Michael K. really sealed the deal.
I think a very close second might be:
March 29, 2011: Philly Boy Roy is stuck at an Emerald Nightmare party! Guy Ritchie is a British Kevin Smith! NJ’s most dangerous theme park, Action Park! PATTON OSWALT calls from onstage in Athens, GA! And PAUL F. TOMPKINS checks in from Australia! What a show!
for the Tom's discussion of going to the Beatles convention, if nothing else. The kazoo at the end, really. "Mistaaaaah Mooooonliiiiiighhhht...."