Evening all, newbie, be kind etc.
Purely as demo discs, I've found the following work extremely well, no particular order.
1) The Dark Knight - scene 20/21, the Joker's attempt to kill Harvey Dent. On a Pioneer 5090 it looks incredible, but beware of using with a panel that doesn't have similar black levels. The full screen IMAX filming helps loads too.
2) The X-men 3, scene 2, the battle simulation. Picture not brilliant as a lot of grain which can be misconstrued as noise, but the soundtrack is fantastic.
3) Planet Earth, most of it. Yeah, 'only' 1080i, but FULL SCREEN 1080i which looks beautiful.
4) The Matrix, You Know The Scene - another sound demo only, as the picture is way too green (I know it's deliberate!) to impress prospective panel buyers.
5) Night At The Museum, all of it - superb to use as a 'running' demo, ie on all the time on a high-end set-up for casual visitors to a store. Picture quality superb, have it running on a Pioneer 6090 via a Denon 2500 BD player and...wow.