"Emotions are important."
Translation:Les émotions sont importantes.
This is a generality, where "emotions" is a category of things, to be translated with a definite article : Emotions (in general) are important = Les émotions (en général) sont importantes.
"Des émotions, comme la joie ou la colère, sont importantes" would be different, because you would refer to "more than one emotion" but not all of them. To translate this meaning exactly, you would probably need "Some emotions, like joy or anger, are important".