No face is finished without pretty eyelashes, and most of us aren't born with long, lush ones. Therefore, I say that mascara is a must.
For girls with good skin, moisturizer, mineral foundation, powder blush, lip gloss & mascara. For those of us who have more to hide, we also need a heavier foundation & concealer. And of course, a brown eye shadow (which can also be used as an under eye liner) is good.