If you want to watch streams through a media player instead of a browser (>2015>using flash) get livestreamer. All you have to do is make sure your player is supported so that once it is installed you only have to modify the configuration file by uncommenting (remove #) the relevant line and making sure the directory on said line is accurate.
Afterwards, open up cmd.exe (easiest access through super/windows key) and type in "livestreamer link.com/stream low/medium/best" et voila.
Here are all the relevant links:
June 15
EA
Time: 1:00 PM PT / 4:00 PM ET / 8:00 PM GMT
Length: 60 minutes
twitch.tv/event/e3
Ubisoft
Time: 2:45 PM PT / 5:45 PM ET / 9:45 PM GMT
Length: 60 minutes approx.
twitch.tv/event/e3
Sony
Time: 06:00 PM PT / 09.00 PM ET
Length: 60-120 minutes
twitch.tv/playstation
June 16
Nintendo
Time: 9:00 AM PT / 04:00 PM GMT
Length: ˜60 minutes
twitch.tv/nintendo
youtube.com/user/Nintendo
Square Enix
Time: 10:00 AM PT
Length: N/A
Twitch.TV/SquareEnixPresents
Youtube.com/SquareEnixPresents