I've already accumulated quite a few presser feet for my lovely new machine, and am proud to say I used quite a few of them this weekend:
1C Reverse pattern (of course--this is the all-purpose that you can do most basic stitches
3C automatic buttonhole with slider--for a little dress I made for a friend's baby due in August
7 Tailor tack--for (drumroll, please) tailor tacks on a suit I'm making for ASDP/Threads challenge
10C Edge stitch--a few people have named this as their favorite foot, and it is def one of my faves
16 Wide Gathering--also for the baby dress. Loving this foot after getting the hang of it.
18 button sew on--have one for my Elna, but never used it since it seems easier to sew buttons by hand. No more--this foot works great, as does the button sewing program
35 Invisible zipper--SOOOO much better than the foot for my Elna which required me to sew twice to get it just right. The Bernina foot is perfect the first time, so it now takes me half the time to put in an invisible zipper
I still covet a few feet I don't have yet: Binding foot, Ruffler, piping. I am trying to get myself to master all the feet I've already bought before buying more. Will post again when I've tackles a few more...