Presentation wise MS took the crown for me. Backwards compatibility, pro-controller, ReConnect (from the looks of the CGI trailer) and Rare collection have made me decide that I will eventually buy an XOne, which is huge for me, since I wasn't really planning on buying it... ever...
I always knew I was going to buy a PS4 (don't have it yet) and Sony's press conference didn't convince me to buy one this year, meaning I'll probably get it in the Summer of 2016 when the games are actually there... It's great that Shenmue and FFVII remake are coming, but 2017, sheesh, that's a long way away. They could have just announced them next E3...
Nintendo... I'm a huge Nintendo fan, and I love my WiiU and New 3DS to bits, but that presentation... made me sader the longer it kept going. I was smiling at the beginning. Loved the quirky intro and the StarFox gameplay reveal, but after that... I am really excited for the new Mario & Luigi on 3DS and will play that multiplayer Zelda game on 3DS, but no real WiiU megaton? Shame shame.