I think the best thing for dark circles is to NOT use a heavy concealer. In my experience heavy concealer actually makes them worse and more pronounced. When you use a thinner consistency concealer you do not get the cakiness and cakiness can actually make dark circles appear worse.
Many makeup artists use a peach colored concealer because peach/orange is opposite of blue on the color wheel so it cancels it out. Bobbi Brown makes a peach corrector. I also think when working with concealers it is important to "warm" the product up. On the back of your hand dip your ring finger into the corrector and then tap tap tap onto the back of your hand. This warms up the product and thins it out giving it a better consistency to go on your eye now. Do not wipe or slide, use a tapping motion. Start with the smallest amount possible and then do a slight building by using the tapping motion. Eve Pearl also makes a corrector. It is called Eve Pearl Salmon Concealer I think. It is very similar to Bobbi's correcter. Maybe a little more opaque. You can get Eve Pearl on Amazon, Ebay or Eve Pearl.com. You then choose your shading. You may want to check out Bobbi Browns first because you can actually see it there and play with it and have a SA help you out with it.
Another good one isn't a concealer at all but a highlighter, Yves Saint Laurent Touche Eclat. Many people have good luck with this whether used alone or with (lightly) your concealer or corrector. It brings light to the face, it is thin and not too thick so it isn't cakey, attracting more attention to that area.
Another very good one is Makeup Forever 5 Camouflage Cream Palette. You can find this at Sephora or their website. It is 5 different tones and they do have a peachy one. MUF is a bit thinner in consistency than BB or Eve Pearl. Again, use the back of your hand to warm it up and thin it out a bit by tapping before you start tapping on your eye area. You can actually see this product at Sephora before buying and try it out and see how you like it. The nice thing about this is that there are an additional 4 other concealers so you can mix to your tone.
For something like looking for the best concealer for you dark circles, it is good to check out all the makeup counters and just dig in and try different things until you find something you like. Let the SA know what you are looking for and then she can point you in the right direction.
Anyway, hope this helps! Good luck!
Those who make peaceful revolution impossible will make violent revolution inevitable.
JFK