What is the most important thing?

When you buy makeup, what are your primary criteria—besides a flattering color match? For example, must your foundation contain sunscreen before you will even consider it? Do you love or eschew the feel silicone-based ingredients? Do you abhor cream eyeshadow? Do you prefer lip gloss or lipstick, with no chance of merging the two? When I wonder about these questions, my mind drifts