Or if you are looking for THE eye shadow, THE must-have, THE must-buy, THE one that fits everybody... Which one could it be?
MAC Paint Pot Constructivist.
It's creamy, high-pigmented, does not smudge during the day, it really stays in place, you can blend it very well, you can use it for smokey eyes, you can apply it lightly as well as strong and dark, you can even use your fingertips to apply it. And the brown shimmery color fits every iris.
Here's the proof:
|my own color: blue-green-turquoise-something ;-)|
|blue (thx. Photoshop)|