MINECRAFT

[Vipershark]

Creepers are easy as shit to kill UNLESS they sneak up on you.

As long as you have enough space to run (quickly), they can't catch you. They move far too slow.
Even if they're fizzling, if you're at a certain distance away, they WILL NOT go off. Once you find this distance, you can get relatively close to them and have nothing happen.
If you get a creeper in water, his explosion will do a maximum of one to two hearts of damage, but his explosion range is extremely short. Because of this, it's possible to take a creeper blast full force, and take no damage.
Like I said before, the door trick is the easiest possible way to kill any enemy, creepers included. As long as you're on the other side of a wall that's at least two blocks high (doors count), creepers will not explode. You can use this to safely kill them.
If you're standing on a wall in front of a creeper that's at least two blocks high, they generally won't explode and will just stand against the wall while continually jumping. All you have to do is look down and attack when its head reaches the highest point of the jump.

Once you learn their AI, creepers are pretty basic.

I find spiders to be overall the hardest enemy to kill. Fortunately, I encounter them the least.

Skeletons aren't hard as long as you don't get too close and continually strafe. You'll have to learn the "safe" angles from which you can get close to them but be out of the way of their arrows.

If a skeleton and a zombie are both coming after you, try to maneuver yourself so you get the zombie directly between you and the skeleton. The skeleton will fire an arrow which will hit (and damage) the zombie. The zombie will then turn around and attack the skeleton. If he successfully damages the skeleton, the two will start to fight, giving you time to get away.