You know the one I mean!  That silly little filler 
scene that made you giggle like a loon when you 
saw it in the show, but would never have gone onto 
your wishlist with all the "respectable" cels.  
^_~  Then one day you saw it up for sale, 
squealed, and leapt on it with the same sense of 
triumph that would have accompanied a true 
dream-cel purchase.  *grin*

For me, it's Canal in a chicken suit.  How about 
you?