I missed most due to my internship, so for what I saw:
Sony: A-
+ So many bombs. I mean, I don't even like Final Fantasy but I totally felt that one. Very happy about Last Guardian as well.
+ Saw it in a movie theater.

- Didn't like the Kickstarter being announced there, even if it is a game I'd love to play.
- Wished to see more on Amplitude.
Nintendo: B-
+ Star Fox! And it's totally Star Fox 2! That's awesome because Star Fox 2 is amazing.
+ The Legend of Zelda continues to be really rad.
+ Mario & Luigi x Paper Mario. Too bad it's really a M&L game, because I much prefer Paper Mario games.
- Good job with the Metroid and Animal Crossing trolling!
- No Rhythm Tengoku.

- Nothing overwhelmingly amazing announced for the first time, though Zelda is personally great for me.
I feel like that if Nintendo held back some of their recent announcements, they would have had a better digital event. Overall, though, Nintendo's presence at E3 is an A- because of the tournament and the Treehouse thing, but the digital event was a downer.
The, uh, PC thing: B
I'm not terribly interested in most of the games shown, but they actually showed a lot. It was rather long, though. Next time, they should do sizzle reels.