In terms of broad industry hype, probably MGS2.
Followed by either, 1. E3 2004 and probably whichever franchise you preferred: MGS3, Halo 2, Zelda Twilight Princess (Probably the most hype E3 too.).
Or, 2. something from Warcraft or GTA... probably an early WoW trailer or maybe... GTA SA or IV, because MMOs and GTAs sort of cause people to hype and obsess over details for a long time because they're sort of 'live a life' games rather than 'experience a story,' so you'll have people analysis every detail and get hyped about how it could be a week's worth of free roam open-world lifestyle gameplay.
So, one of those 5 would probably be the top choices IMO depending on the type of gamer. But I think MGS2, even though I'm not actually a fan of the game, was still the broadest and 'most hype' trailer reveal.
In terms of pure quality regardless of the size of its reception.... just pure, surprise hype, hype creation... Burnout 2