RE: Microsoft
Out of the gate, they were dropping pretty massive titles that I know I'm going to be buying with the platform I already have. Games like Rock Band: The Beatles, Modern Warfare 2 come to mind early, but that is going across the board. I was definitely most-excited about the new Halo titles, particularly Halo: ODST, which will add an interesting new layer to the franchise. But, the main titles that had me excited were Crackdown 2 and Forza Motorsport 3, two franchises that I absolutely love, one of which will be here in October.
Then there was Project Natal. That by far exceeded Wii Motion Plus and whatever Sony is calling their new system. It breaks barriers, and becomes hauntingly awesome with their Milo Demo. I have to give props to Microsoft with their Facebook and Twitter integration that will be coming to XBL, which makes a lot of sense, but will also open up some very interesting channels when it comes to playing with your friends on either network. The changes to Netflix are welcome as well, because browsing videos through the 360 will make things much easier, and certainly be a nice add-on for when you don't feel like getting up to add a new title to your que.
RE: Sony
Sony came in an extremely (and otherwise surprisingly) close second, due mainly in part of a lack of two things:
1) Any kind of release date on Gran Turismo 5
2) Any mention of a price reduction on the PS3
If either of those had been included, I'd have been inclined to give the win to Sony. I do have to give some massive props for the Mod World Racer game, which looks like a TON of fun. The same can be said for MAG as well, which could have some absolutely EPIC firefights if the 256+ player number can be stable online.
So, I'm waiting for more on GT5, MWR and MAG. Otherwise, there isn't much for me from Sony.
RE: Nintendo
Don't get me started. There wasn't much to talk about, outside of the surprise Team Ninja Metroid announcement. I didn't get into the previous Metroid titles on the GC, I'm not sure how this will be a whole lot different for me.