Your pick for most underrated TFTC episode?
Confession. Yeah, that's right, I'm going right to the dreaded season 7!
It has plenty going for it, like some really cool Se7en-inspired art direction, clever dialogue between the main characters, and Eddie Izzard hamming it up. It does end a bit inconsequentiallly, but I still get a real kick out of it.
If you must blink, do it now.