MAC Pro Longwear Concealer - Retails for $19. This is described as a "lightweight fluid concealer that provides medium to full coverage with a comfortable, natural matte finish."
CON : The main reason why I got this concealer was because I heard it was great for under eye lines. I find that this still settles into some lines, while covering others very well. Maybe it's user error and I need to apply less (or more) so please let me know how it works for you if you own this!
I would definitely still recommend this for someone looking to cover dark under eye circles. The fact that you only have to apply this once and not have to worry about it for the rest of the day is amazing!