This is a user made video of SC, gives a good look at all 3 races, some of the units for each race, and the excellent graphics detail that SC has. Music isn't bad either.
http://forums.gaspowered.com/viewtopic.php?t=4817
The DIVX link (first link) is the best quality video.
Supreme Commander: The Art of War (Video)
Moderator: RLG MGMT Team
Supreme Commander: The Art of War (Video)
"SILENCE, I KILL YOU!!" - Achmed the Dead Terrorist
AKA: Staark or Staark_RLG