I started with the Westalee 6-piece ruler set and really love them! They're the ones on SewSteady.com. I've recently discovered Amanda Murphy's rulers. She has sets of every circle, every oval, every wave, every star, every angle, lollies, and ribbon candy. I use all sizes of circles and ovals quite a bit, so was pretty excited to find these. If your machine can take a high-shank ruler, HandiQuilter has a ruler of the month club, where the rulers are only $20 each, which is a really good price.