I have a combination of brushes.
My main powder brush is a MAC #129 powder brush that I use for my blush.
I own Sephora foundation, medium eye shadow, and concealer brushes. I like the shadow brush the most, foundation and concealer brushes are meh.
I absolutely ADORE my Too Faced "Teddy Bear Hair" brushes that I bought for 20% off. Lip brushes, blending brushes, the whole shabang. Well worth the $ and then some.
I also bought a cute smudge brush from Target's line of brushes the other day and it works like a dream (I only paid $2 and some change for it)!
I'm planning to look into Sonia Kashuk brushes.