Various Crisis Core videos for those who haven't seen anything yet:

Cloud Strife
Zack Fair
Zack Fair 2
Aerith Gainsborough
Sephiroth
Angeal Hewley
Genesis
Tseng
Cissnei
Lazard
Cinematic Japanese Trailer
Trailer
Japanese Intro
Japanese Trailer
Japanese Trailer 2
Battle System
Materia System
DMW 1
DMW 2