Peach is one of my very favorite authors, and I love just about everything she's written. Her Skinner/Krycek stories are my favorite, but I'm happy to read her Firefly stories and those that are set in Smallville.
Of Peach's completed stories, Things That Go Hump in the Night is my favorite. If There's a Bathroom on the Right was finished, however, I'd have to toss a coin to declare the winner.