Taken - The human like enemies of Alan Wake are called the "Taken." They were once humans that are now possessed by a "Dark Presence." Taken have a shield of darkness that protects them from injury. Use some type of light to take away this shield and then you can kill them with normal weapons. There are different sizes of Taken:
Regular Taken: Just regular people that use axes for melee and pick axes for throwing. On Normal they can take about two shots from a revolver after their shield is down.
Quick/Fast Taken: These Taken are a lot faster and melee you. They will teleport around and you won't be able to see them much. They will slow down to stab you. Once their shields are gone they will stop speeding around. On Normal, once their shields are down, they take one shot from a revolver to take down.
Strong Taken: The strong taken are usually bigger than most taken by a bit and carry sledgehammers that hurt you real bad. With the addition of using a sledgehammer they can charge at you like a bull to do some damage.They have bigger shields than the other taken and can take more damage. About 4 times more damage I'd say.
Boss Taken: These can vary with size and speed. They're usually both strong and fast and some can teleport across the screen. They all have high shields and even higher damage resistance, by about 9 or 10 times.
Ravens - Ravens aren't very strong by themselves, but once they're in flocks they can destroy you. They are very hard to hit with regular weapons so it's best to kill them with boosted light or a flare gun.
Poltergeist Objects - Even objects can be enemies in Alan Wake. Various objects like barrels and gates and other scenery can be possessed by the darkness and fly at you to injure or even kill you. To destroy them you need to use a light source. If you don't destroy them the first time they fly at you then they'll come back again and again. If they're within a certain range of you using a flare then they'll stop moving until the flare ends.
Black Goo - Hardly an enemy but it can hurt you! You'll find black goo all over and if you touch it then it damages you. Just keep your light on them and they die quickly without moving.