For those that do not know, there is a very large artistic graphics demo scene that has been alive and well in Europe since the early 80's along side the releases of Commodore 64 and Amiga. Each system was a bit ahead of its time especially the amiga as it could do 4096 colors at once in HAM mode (still images mainly) and this was 1985 !
Some of these groups are still around today and should be working for game companies if they do not already.
This demo has buildings etc all made from god only knows how many particles and kicks my 580 oc'ed to 933 2600k at 4.7 to its knees. Still, despite the low fps the demo looks amazing. Drop to lower res doesnt hurt the visuals too much considering everything is particles. There are a few demos on this link that are up for "Scene Awards" for 2011. Check them all out if you like however Ceasefire
is the one I am speaking of.
Another uses particles as well made by the same team called Agenda.
Want some pure eye candy ? These particle demos will kick you cards right in the jewels so be warned.