The Damon/Murray/Bonneville one was a classic. Especially Damon's story about Murray taking a train to (I think) Poland the night before a 9 AM shoot (the best part was Murray's response to Damon telling him he'd never get back in time: "Yeah, but I've never been there.")

I was gonna also mention Springsteen's "Roulette." A River outtake but it resurfaced on Tracks and the most recent box set…

The Dwarf kicking Stonehenge around like a soccer ball still may be one of the greatest sight gags ever…

I believe Anthony Bourdain was begging to do a guest spot on Archer for years and finally got one in the fourth season ("Boom! Bumper!")

Hopefully it lives up to the Simon & Simon one (tho that'll be tough, since they can't have Jon Hamm die of hypothermia—in San Diego—again)