Which accessory foot do you love/use the most?

There are so many accessory feet available. Not just the handful that come with your machine, but a gigantic wall of them.

Most of them are technique oriented (like getting the perfect button hole or creating your own candle wicking).

Which one do you love or use the most?

My current favorite is a narrow piping foot - just because it makes the job so easy!

I love my walking foot!  It is great for projects with lots of layers like bags!  I am just now making my first quilt, and I know it will essential for that as well.

Walking foot definitely. I have a bunch of others but the only other ones I use are the zipper feet, invisible and regular. I've been sewing for years and I always forget about the other feet, I don't even know what they do, isn't that terrible?? Probably could be saving myself time and trouble!

I do love the gathering foot on the serger!

I love my 1/4 inch foot.  It is so great for sewing around the 'edges' of things. And gives such a nice professional straight line that I know I would not be able to sew otherwise.

I have a Bernina and I use the #10 edge stitching foot heaps. It makes the finest straightest edge. I mentioned and showed a picture of it's capabilities in this post: http://badskirt.blogspot.com/2009/04/my-creative-space_16.html

It also does lace and helps with binding without the cost of a full binding foot.

I use my walking foot alot but I love the 1/4 in foot for everything else.

I too love my piping foot.  Stuff turns out great every time.

I have a clear embroidery foot that has arrows and lines.  I use it all the time.  I like that I can see where I am sewing.