I have lots of built in stitches on my old Pfaff 1475, but rarely use them. When I do, it's usually the more basic fancy stitches rather than the more complex embroidery stitches.
I use the blanket stitch, the herringbone, all the zigzag stitches all the time, but I can't remember the last time I used the decorative stitch.
The exception is the lettering, which I use a lot - it's far easier than sewing on name tapes.
My Bernina 730 has a lovely ricrac stitch, but that is the only fancy stitch I use on that.
The Singer 611g has some nice decorative stitches, but up to now, I haven't used them.
Jessie