Launch trailer

Aired on the pre-super bowl game where an estimated 65 million viewers watched.
Voted 2nd best game trailer of all time by users of GameTrailers.com

Cinematic Trailer- 30 second cut

Included on every Mass Effect 2 game disc

Mass Effect 2 Enemies- Developer Diary

Mass Effect 2 Character Trailer- Samara

Mass Effect 2 E3 Prelude- Developer Diary

Mass Effect 2 E3 Reveal- Developer Diary

And many more can be seen on BioWare’s Mass Effect 2 Playlist
http://www.youtube.com/playlist?list=PLED6585BB14456B50