A lot of names come to mind. I mean, I won't complain when a pornstar leaves the business after ten "productive" years, even if I'd like her to do some more. For example Tawny Roberts. I'd love to see more stuff of her, but she has been in the business for seven years and for her personaly it was just time to "move on". Nothing to do with being a flake or just having wanted some fast money.
So, I'd go with
Kiwi Sweet
Desert Rose aka Kody
Luna Lane
Shandra Lebre
Tiffany Holiday
Adrenalynn
Lily Thai
Halia Hill (I'm not sure about that, but rumor has it that she's gone already.)
Celia Blanco
....