I swear by my Marc Jacobs The Face II for liquid foundations. It's also really nice to buff in powder foundations, since I don't have a kabuki that I like. The fibers are really dense, and it's synthetic bristles, which I prefer.
I've also rekindled my love for my MAC 187, which I use for BB creams and any other liquid that I want to achieve a light coverage with. It's also really nice for creams, gives a beautiful airbrushed finish.
Both of those are on the high end, though, I think each run around $45. I like Coastal Scents for more affordable brushes, but I have never used any of their face brushes, only the eye brushes, so I can't speak to the quality or effectiveness of any of them. Sorry! :blush: