As different shows are coming then I start to revise what I thought of others:

Bethesda : 7.5 - Hardly any games to show, but loved seeing Fallout 4, and the Doom demo showed how to do a demo right, all action, great kill shots and fun. Thought it was CGI to begin with.

MS : 6.8 - CGI, Games we already know about and franchises, new games CGI, not fussed by holo lens. But had a good pace and tried to cover different genres. EA access was a bit weird. Halo videos/gameplay was very flat and so was Gears of War. Positives for fans was backwards compatibility.

EA: 5.6 - Mass Effect CGI was wonderful, Pele - what in the world...sports sports sports of franchises that we've seen a million times before. Star Wars was amazing, and is currently game of the show with FO4. In fact If EA had just come on and done ME and SW I would have given them an 9, but all the other boring stuff... forgetful

Ubisoft : 5.2 - Wide range of stuff, not bad pacing, new IP that battle clone thing, looked ok. Dance game...omg why bring a singer on stage...nearly made it awful. Ghost recon looks interesting, but is it MP only, The Division looks like it was downgraded, Ubisoft now showing console gameplay to ensure peoples expectations in check. Not really that much interesting, AC CGI was very impressive, but want to see gameplay.

Ubisoft for me has better presentation than MS and EA. haven't watched Bethseda in full yet though.

EA lots of sports, then I don't get DAI and Sims 4 that doesn't have any expansion? Still great ME andromeda trailer though.

MS has cool stuff especially the controller and BC even with an initial list of games for now.
Hopefully better conferences for the remaining ones - Sony, Nintendo and SE

Bethesda - 6/10
Microsoft - 7/10
EA - 6
Ubisoft - 7

So far I only watched MS. I have some catching up to do.

MS - 8/10. Recore, Rare collection, BC, and Gears 4 was good. The controller, Sea of Thieves and the rest were okay.

Sony 9/10 (minus 1 for the boring bits towards the end)
Bethesda 8/10
Microsoft 7/10
Ea 3/10
Ubisoft 7.1/10

Ubisoft is winning so far. Im loving the look of AC Syndicate. For Honor surprised the hell out of me. South Park is gonna be amazing.

MS=NWC > Bethesta > Ubisoft > EA

NWC started slowly and with an annoying kid, but ended in an epic way. MS did a good job. Bethesta did a great job, but lacked content. I doubt they can make a conference every year.
I think For Honor is a good idea, but AC turns me off hard after the 4th. EA managed to be slightly worst.

Bethesda- 8
Ubisoft- 7
EA- 5
Microsoft- 4

I'm still trying to figure out who is gonna be playing Mass Effect 1 in 2016. The announcement of BC sounds good on paper but it seems more like a PR move.

Fallout 4 looks amazing.