I downloaded a game called Super Stardust HD on to my PS3 from the Sony Store the other day.
The reason for mentioning it is that it is it is the most stunning piece of computer generated visual graphics I have ever seen. A lot of the initial games for the PS3 looked liked they were carry overs from the PS2 but this one is an absolute treat and hopefully the sign of things to come as programmers start to fully utilize the power of the this next generation of machines.
I've got it running on a projector via HDMI from the PS3 and even at 720p its stunning.
Basically the machine has to render hundreds of falling asteroids and a rotating earth and surroundings in real-time, impossible on earlier machines. This is reminiscent of a game called Asteroids I had way back on my Commodore 64 where the space ship was a triangle and the asteroids were polygons, all in monochrome.
It also highlights the better end user experience with the new machines' network capabilities i.e pay for it and download it over the internet, gets stored on the hard drive and plays with little loading delays etc.