So far I've watched the stuff for Halo 5, Dead Rising 3, and Metal Gear Solid V.
Halo 5 reveals effectively nothing. It's just a trailer featuring what looks like a gigantic Forerunner robot moth in the desert, and the Chief wearing a burlap poncho over his armor for no reason whatsoever.
Dead Rising 3 is something I'm interested in, but it's unfortunately slated to be an Xbox One exclusive and I really don't want to buy one. It's got the same basic gameplay as the previous games, but a bit slower paced and more realistic. Takes place in a full city now, with destructible environments (both the player and zombies can smash down fences, for instance). You can take time to build at least some weapons or modifications, like a sledge-saw or taping a flashlight to a pistol, without needing a workbench. And you can use the SmartGlass to interact with the game, including calling in airstrikes.
Metal Gear Solid V is looking the best out of the trio. Impossibly good looking, with open world environments, vehicles and horses, and a far superior combat system that seems to make it practical to actually go loud and shoot (including "dynamic CQC", one of the tactics being disarming an enemy and shooting everyone around with his gun). Hopefully they've learned from the previous game and won't make it 9 hours of cutscenes interspersed with 10 or 20 minutes of gameplay each.