I would strongly recommend going to a department store and visiting the Clinique counter. I promise I'm not a rep. Also, check to see if you have a Sephora's where you live... that would be the best bet.

Get a concealer that is just a shade/touch lighter than your foundation/skin color (your foundation should match your skin color) because you will want to "lighten up" the area under your eye to appear fresher looking and well-rested.

The reason I recommend going to a department store or Sephora's is because an objective eye is the most useful when you are buying makeup.. they will be able to consult with you about your skin type (oil, dry, combination) and about your needs (heavy, light coverage) and pick something that is just perfect for you.

A Clinique concealer is usually price from $13.00... a Covergirl one is about the same price.

Also remember your foundation ... is it water or oil based? Pick a concealer that is the same base as your foundation because... well.. oil and water don't mix.

Also... if your problems are really bad.. try corrective concealer. They come in light green and bright yellow... green counter-acts red and is perfect for red pimples and irritation and yellow counter-acts purples and blues and is perfect for under-eye circle correction.

Good luck!

Also... try MAC makeup.