From my experience and usage so far, I have to say that for me (and I have circles, not bags) the ones which cover and camouflague are the best. I was advised by an Illamasqua make-up artist to actually use one that covers and then one that highlights/reflects. This did work, but if you're watching your pennies, it may not be the best option.
So, Im writing this entry today, because in the last week, I think I may have found THE best dark circle concealer I have used so far! Where is it from? It's from a brand which Ive been using since my early teens; the wonderful MAC! The Select Cover-Up in said to be 'liquid camouflage for the skin.' When I was chatting to Heidi the artist about it, I made it clear that it had to fulfil two factors: One, cover my dark circles and two, not dry my already dry skin out! I have to say that it scores full marks on both points. There's a beautiful, creamy consistency to it and you really do not need to use very much. The price of £12.50 in my eyes (pardon the pun!) is well worth it!
I will also add that I think for concealers and foundations, it's so very important to seek advice from one of the artists in store. As far as MAC shades go, I am an NC shade for my face (cool) and an NW shade for my concealer (warm) This I was told, is because our circles are often shades of blue/purple which are cool and therefore need to be neutralised by the warm (NW) type shades. See, you learn something new every day!
Have a good weekend popsicles.
Belle x