Well, it's not really a stencil piece, but that was the nearest possible category... uhms.
A client of mine wanted to have a Sin City-themed painting on his livingroom so made him one. Original artwork is by Frank Miller (much respect) and it features his Marv-character.
The piece is roughly 5m wide, 1m high and is done entirely with spray paint. Took me some 9 hours to do it.