For reference, maybe use the ones from MAC, or just say the kind of brush (ie contour brush, angle brush)
I desperately need to replace my brushes.
239 - great eyeshadow brush, all over lid
217 - great for crease; eyeshadow.
224 - great for bledning harsh lines from your eyeshadow
a stippling brush is great for applying foundation AND blush
I swear my bobbi brown's eyeshadow brishes. not cheap, but if you clean them regularly and use them correctly they'll last forever
These are some of my favorites from MAC:
But definitely feel free to try out other brands, MAC isn't the only company with good products! I really like Sonia Kashuk (from Target) and Japonesque (I found mine in a some department store, but I think they're sold at Ulta as well). Good luck!