Example 1
Even though there were only two of them, each person in the audience reveled in my performance.
Since the speaker performed for a massive crowd of two adoring fans, each is the right choice here.
Example 2
My great-aunt has thirty cats, but she really does love each one with all her heart.
Did you know that a group of cats is called a clowder? And a group of kittens (squee!) is called a kindle? We bet that the speaker's great-aunt does. In this sentence, each is the right choice because the speaker wants to emphasize that her great-aunt loves each cat individually.
Example 3
I will taste every Baskin Robbins ice cream flavor or die trying!
It's good to have goals. In this sweet sentence, there are more than two items, so every is the correct word.