I can't vouch for their Kontakt banks but have their Virtual CZ patch bank and it is great. I own a CZ101 though which makes it worth more to me.Kalamata Kid wrote: Should Home Grown Sounds http://hgsounds.com/product-category/kontakt/ be in this list.
The examples above are all distinguished by their ability to stretch the functionality of Kontakt with specially coded interfaces and interesting source material. K5 is great if you want to go in that direction.
You can load your samples into Kontakt, and make your own banks, though it's not intuitive and I found it wasn't especially rewarding.I am only interested in synths that allow me to use my samples as sound source.
I am generally not into percussion.
MachFive3 (and Padshop Pro to a certain degree) allows you to go to town mangling and layering your samples. Aside from owning one of Simon's M5 banks I only use my own samples in it.