there is a jackload here http://www.zeograd.com/
Where exactly? All I'm seeing are emulation stuff. When I mean demos I mean graphical demonstrations that show off a system's capabilities in a non-game context like these:
Second Reality by Future Crew (PC):
(the best demo ever created, with the best music ever (GET DOWN!))
Nexus 7 by Andromeda (Amiga):
(this one rules point blank)
The Popular Demo by Farbrausch (PC):
(this is just BEAUTIFUL)
The Morning Trip by Loonies (Amiga):
(Yes, real-time cel-shading (well it might be pre-calculated) and PUMPING Amiga techno!)
EDIT: I see the TG-16 demos now, thanks for the link! I'm gonna try the Axelay one...
EDIT EDIT: fixed link thanks to malducci! ^__^