To start things off... This has probably been posted, but when I searched the forums for this, all I could find was suggestions for hatches in general. Also, this is a very short suggestion, because its an extremely obvious thing that should have been added in the first place along with wooden hatches. Anyway, I am proposing iron hatches. They can only be opened from Redstone. This would make things like drawbridges much easier, as people could not just close them after they have been 'raised'. The recipe would be the same as regular hatches, only with iron, and you would get 2 iron hatches from it. I thought this would be an extremely obvious thing to add in the hatches update, but I guess not...
Iron Hatches