In my life? Mario 64 has to be a contender for the greater picture.
But my #1 will forever be this:
Killzone 2 From e3 2007.
For those not familiar with PS back then. In 2005 Sony showed off a KZ2 trailer that looked PHENOMENAL. New CEO Jack Tretton mistakenly said at the time in an interview post conference that it was in game footage. This ended up not being true. There are several accounts of what happened, but I believe officially he said later in a separate interview he thought they were referring to Resistance (iirc), and confused the titles.
This was one of many PR hits the ps3 took early in its cycle. People mocked Sony for this, saying it would never be possible.
Guerilla took that personal.
In 2007, news broke that they had finished KZ2 and the graphics would be earth changing. Much skepticism occurred, naturally, culminating to a secret pre-event that was invite only before e3 2007, and didn’t allowed recording.
Now, flash back to message boards at the time. I frequented the official PS boards mainly. The hype was brewing. N4G, a website at the time that was heavily Xbox skewed (in modern gen that has virtually flipped) was flooded with leaks and news. The official PS forums - I remember the official thread getting massive, and finally a grainy sneaky recording came out showing a brief bit of the rag doll mechanics in a Helghast being shot.
Holy. Crap.
E3 2007 was, IMO, the turning point for Sony. Their conference came with massive hype, trailer after trailer and industry speak. Then… the last segment came. “We have one more thing”…
Then the trailer starts… which starts off the same way as the CGI trailer from years earlier. And then what we saw afterwards became a major gear in turning Sony in the direction that has led them back to the forefront today.
That was the first of 2 major “mic drops” from Sony (the no DRM e3 being second) and my favorite e3 of all time. I will never forget the applause at the Sony conference afterwards and how much the talk shifted regarding what the ps3 was capable of following.
Epic.
So yeah, KZ2 is mine. Still my favorite shooter of all time.