Another review for you here :)
I have tried and tested a number of concealers for a number of different problem areas that I have and I have found a few that work for me. Most of these products are from a drug store so they are very affordable.
Maybelline Fit Me (Shade 20 and 10)
Rimmel Wake Me Up
Maybelline Age Rewind Eye Eraser (Light)
L'Oréal True Match (2 Vanilla)
No7 (Cool Rose)
Mac Pro Longwear (NW20)
MUA Pro Base Prime & Conceal
I do find that I change up my concealer depending on the look I am going for any how much coverage that I want.
I feel the one with the most coverage and that I tend to go to for a night out or special occasion make up look is the Mac Pro Longwear. It covers under eye circles and any spots/blemishes well as it is full coverage and it lasts the duration.
For my every day make up look, I usually reach for the eye eraser or Rimmel wake me up, to help me look more awake and to add a subtle highlight under my eyes.
The No7 I did find covered my under eye circles well but I used this underneath my foundation rather than on top like the other concealers that I have as it is in stick form and not liquid.
The MUA Pro Base is a good cheap all round product which I bought to take on holiday when I wanted to wear minimal make up but still had under eye circles and spots to conceal. This worked really well with my BB cream the different colours in the palette covered the different problem areas that I had without the need for me to take more than one concealer on holiday.
All of these products blend out really well with my fingers, a brush or my beauty blender.
Maybelline Fit Me I believe is a good dupe for the Nars Radiant Creamy concealer, and I do have this in 2 shades depending how tanned I am, I can change it up to adapt to my skin tone.
Another concealer that I absolutely love (but have just ran out of and cant find my colour anywhere as it is so popular) is Collection lasting perfection concealer in the shade number 1. It is less than £4 and is a dupe for Urban Decay Naked Skin, it has really good coverage and blends out perfectly, giving a good highlight under the eye too.
If you are looking for an affordable concealer with good coverage, then I would recommend that you try this one. The only downside is that it only comes in 3 or 4 shades and the lightest one is quite light!