I have an irrational distaste for certain pasta shapes. I almost never buy macaroni - even if I'm making "macaroni" and cheese. You can forget rigatoni. Farfalle is another scorned pasta, but sometimes it does find its way into my kitchen. Then it sits there for 6 months while I purchase more desirable shapes like shells or spaghettini.
Eventually I come to the realisation that I should probably use the farfalle. This happened the other day and resulted in a comforting and filling pasta e fagioli, which was inspired by the lovely and amazing Shutterbean.