Just in case anyone missed it- if you don't view all the briefing files in MGS1 you'll get an alternate cutscene.
Speaking of alternate cutscenes, there are 4 more that I recall.
- Completing the VR Missions prompts a comment from Snake during the Codec conversation on the Helipad.
- Not picking up a SOCOM prompts an alternate cutscene with Meryl, with different music.
- Not being spotted up to the air vents in the Tank Hangar omits the cutscene where the guards discuss about a second intruder.
- Killing the Ravens will prompt a comment from Vulcan Raven when you meet him.
- Calling Miller during the before he tells you about Naomi will trigger a correction from Miller regarding the Ravens, as Snake mistook them for crows. This carries over when you call Otacon as well.
Didn't know about the VR missions or not picking up the SOCOM, but the rest of that stuff I remember.
I remember Master tells Snake that he's part Japanese, which would explain why Raven says that "we share many ancestors you and I." I forget what you have to do for that one, probably call Master after the Raven fight.