I can't live without either 1/4" foot that has the little metal guide or the older style "patchwork" foot that has a little tick mark at the 1/4" on each side.
I also use my walking foot for putting on binding and stitch in the ditch.
I use my open toe applique foot for machine applique, paper piecing & zig zags.
I haven't used my darning foot since I got my mid-arm but if you plan to FMQ, you will need it or a hopping needle.