i frequently end up buying rulers when I take a workshop with a teacher--so have bought from DeLoa Jones (her boomarang rulers are wonderful!), Jaimie Wallen (who has handles on his); Linda Taylor (my straight edge ruler is from her and my go-to); Kris Viera has a great V that is made just to work on Judie Niemeyer type compass piecing; and I just bought some cool circle rulers from Tia Curtis. Dusty Farrell has some nifty sets that snap together to make circles, ovals, hexagons, etc. Check out their websites! Nice thing is that they also show you how to use them.