A few other fun tidbits -- a few viewers have noted a recurring season-to-season motif of the "half-face" image:
And finally, one of my own favorite images from the last few episodes:
His teeth don't show up as well as I'd hoped there, though. The teeth are key.
Gus is defined through much of Season 4 through a sentient-seeming video camera. Walt's red binoculars played off/against this wonderfully. A great touch. They have a few good shots of them in the finale too.