1. MAC #187. This is the BEST Brush out there, I have two. One for foundation, the other from MSF/Blush/Bronzer etc. It gives a PERFECT finish for foundation.
2. MAC #129. This is an amazing multi-use powder brush. I use it for blush, bronzer, MSF, and powder.
3. MAC #190 or #192. These two brushes are somewhat the same, one's just smaller to reach into tighter corners. Suprisingly, I don't use my #190 for foundation unless for some reason I want to. I use it mostly for CCBs, my Chanel Sun Illuminator Base, or other cream based products. My #192 is perfect for highlighters (Like Benefit's Moon Beam) or CCBs.
4. MAC #266. Great for angled lines, cream liners, or fludlines. Also fun to play around with.
5. MAC #219. Gives of very dark, dramatic color which I love!
And also..
The MAC #222 or #217 - Great for blending or applying extra color!
Hope this helps.