I don't have that many MAC blushes right now, so i can only describe them to you.
peachykeen: pinky color with gold shimmer.
margin: corally/tanish color with a shimmer. i like this one also
loverush: dark burgundy color. too dark for me and i have a tan!
i have a pic in my notepad of those 3 if you want to check them out.
it really depends on what color you want to wear though. i don't really like pink blushes on myself. i'm more into the rosey colors and always with a shimmer.
HTH!