Purple - I'm just not drawn to it so I have to make a point of buying it for my stash. Right now I'm cutting out for scrappy blocks, and still have to remind myself to occasionally grab the purples.
It's not that I dislike purple, it just does not say "come play with me" when I look at it, like the other colors do.
I have a sister that must feel the same way. I bought out her stash, over 300 yards, most in 1-2 yard cuts. And not a purple in the bunch!