That brilliant yellow egg yolk is a surprisingly delicate thing, and separating the yolk from its white without breaking it can be an exercise in frustration. I say forget those fancy gadgets and forget tossing the yolk between sharp-edged shells — the most reliable, sure-fire way to separate an egg is to get your hands dirty.
The method is simple: Crack an egg into a shallow bowl and discard the shell. Lower your fingers into the bowl and gently cup them under the yolk. Hold your fingers loosely, with a hair's breadth of space between them, and lift the yolk out of the bowl. The whites will stream through your fingers and back into the bowl, leaving you with one perfect yolk cradled in your hand. Place the yolk in a second bowl and transfer the white into a third bowl, then continue separating as many eggs as needed.
I like this method for separating eggs for a few reasons. One, your fingers are blunt and soft — there are no edges that are going to snag or break the yolk (though be careful if you keep your fingernails long!). Your fingers are also much more sensitive than any other tool, so you can actually feel how carefully the yolk needs to be handled at any given point. If you're separating a bunch of eggs, you can also go faster — crack the egg, scoop, and you're done.
It feels a little gross and gets your hands dirty, but I haven't had a yolk break on me for years using this method. Do you agree? Or do you like a different method?