The best, IMHO, is the one I have for my old Viking #1 plus...perfect....straight sided, both edges, now on my newer BL the foot has a curved jog on the left side that keeps catching the seam allowance as I sew thru intersections, and the flange one is ok on straight seams, but there again if there's a dog ear intersection or anything, it will get hung up.....and I paid for this aggravation ..