If you want the most coverage, go for a cream concealer. These are harder to blend than liquid concealers, but they effectively neutralize and cover everything you need while lasting for a long time. I use Prescriptives Flawless Skin Total Protection Cream Concealer ($17) and it is probably my favorite so far.
I also use Make Up forever Camouflage Cream Palette No 1 (they come in darker colors and are $36). It has 3 concealor colors and 2 color correctors, this one has orange and green on the left, I saw a darker palette have peach and lavendar. These palettes are good if you are a make up artist, like color correctors, or need a few different colors for different parts of the face. For example, the lightest one covers up this weird scar-thing that I have, but the 3rd one from the left works best for my under eyes. I personally don't use/like color correctors that much, but the range does come in handy for me.