I have three+ that I have made that I would state empathically that are original (as I started thinking through them, I kept realizing more of mine are what I would call original)
(1) first is a king sized that has a wedding dress train down the middle of it along with hand designed appliques and free motion quilting. There will never be another like it I can promise. There was and is no pattern. Even if someone tried to replicate it, it wouldn't be the same. When I was looking for inspiration I found nothing like it in the 3+ years that I looked.
(2) I made a dance/sing/play music quilt from scratch. Again appliques and quilting that can't easily be replicated along with a hand drawn pattern. Now there are patterns for quilts for the background where it is a mish mosh of block sizes but to this day, I have not seen anyone replicate it or another like it.
(3) I made a third that's hard to describe....but in the end it's the FMquilting on it that makes it an original.
I've made lots of quilts that are not originals that are from a lot of inspiration or a pattern by someone else, but quite a few are my originals -- whether appliques or the whole quilt. So my definition of original is that I developed the pattern from scratch. Maybe some inspirations of others played into it, but the ones above are the ones others have seen and emailed me to ask about patterns. Because they didn't exist out there in the market.