I'm a huge fan of Real Techniques brushes and I absolutely had to give their Foundation Brush a try. 

This brush is similar to your standard flat foundation brush, except for its tip. Instead of a tapering tip, this brush has a slanted tip. 

This helps you get into all the nooks and crannies of your face (around the nose, under eyes). The bristles of this brush are very soft and don't shed upon washing. 

I use this brush to apply my foundation when I'm looking for a full, flawless coverage. I apply a thin layer of foundation with this brush and use a dense buffing brush to blend foundation into my skin.
It has become one of my favorite flat foundation brushes.

I will definitely repurchase! I bought this one from Flipkart for Rs. 600