If you're interested in my FULL thoughts on all three conferences, hit up my LJ. There's a bit of colourful language, though, so I'll just summarize it here. XD
Microsoft → Best conference of the bunch. It was flashy, entertaining, and their statistics section was the shortest. Fallout 3 looks great, though I probably won't get it. RE5 looks good too, but I haven't touched that series before. Fable II looks amazing--I'm definitely picking that up, though I'd also like to find the original and play it. GoW2 looks nice but I have to see if I can get into the first one first. Banjo Kazooie on XBLA was surprising, but I suck at the original so I doubt I'll pick up this series. (Ask TRIFORCE89, I really do suck.) The more casual stuff... GH:WT looks okay but lame compared to RB2, which I'll probably be picking up this year. Lips is intriguing but I can't sing so... oh well. :( New dashboard looks LAME. I really hope it's very customisable. But I'm looking forward to the other additions. Live parties, movie sharing, gameshows? I'm there! :'D Avatars were expected. XD You're In The Movies was surprisingly added to my wishlist too. I was laughing at the final movie they showed off with the three actors or whatever and... it looks like a fun game to play with the family. Finally, the SE games look good. I'll probably end up getting a few of them, but I don't know what console yet. Probably at least one on 360 because I'll be picking up the XIII games on PS3 (that announcement really surprised me!).
Nintendo → LAAAAAAAAAAME. Worst conference of the bunch. I was thorougly bored through the whole thing. The only worthwhile announcement was Animal Crossing and I don't even play that series. But yeah, see my original post in this thread for individual game opinions. :/ Cammie or whoever it was who hosted this one was just... augh. Do not want. D: Mind you, I didn't even like Reggie's performance this year so whatever.
Sony → While I didn't actually get anything from this conference, it was still better than Nintendo's. Not that that's hard. XD; Resistance 2 looks REALLY good. @_@ But I suck at games like that and I proooobably won't play it, so I'll just buy it and watch my brother play. Whoo. :'D Aside from that, nothing really jumps out at me. I loved how they showed off their stats and numbers with Little Big Planet though. That was great. ♥ The movie delivery/downloads thing looks pretty sweet, but I'm not sure about it yet. I guess I'll see when I'm back to my PS3 at home. Not much else to say on it though. D:
Dunno what Nintendo's supposed to be announcing today. Whatever it is, I hope they get on with it and give us something interesting to work with. :/ Not that I'll be interested in what they have unless it's a major, major franchise and even then... I haven't been impressed at ALL yet this generation with them (except Brawl). @_@