I only use foundation when I want to be very dressed up and polished. Most days, I just use a swipe of loose mineral powder by Make Up Forever down the bridge of my nose.
When I wear foundation, I love Stila Perfect & Correct Foundation. It has the primer built in, and works beautifully with my wildly combination skin. I buy about one bottle every 10-12 months, and use a makeup brush to apply it, and it lasts longer.