Quote from yadidle
They still have the ability to spook me. Sure, you can get the ones you see, but I sometimes quickly swipe my mouse across the screen to do a quick survey of the area. Since the endermen are dark, it's hard to see them. Every once in a while I'll have one teleport to me for no reason, and start beating me to death, only to realize that it's one I briefly glanced at.
I've also had it where the instant you look at them they teleport out of sight completely. No where to be seen. Once I forget about them, they always find a way to teleport back to me and scare the living crap out of me.
They're not as creepy as they could be, by all means, but they're spooky to say the least.
About this: A long time ago when notch first described enderman he said something along the lines of "Never wanting the player to be confused if the enderman were to teleport" (somewhere on his tumblr i think)
Your confused =/