I never quite finished this one, though I was very charmed by it. I should go back and do so. Which of the short stories would you most recommend, Idgo?
Oh jeez. That's a tough question -- most of them interplay with each other in a way that I fear might be lost if they were taken in isolation.
For mindfucks around time and timing, try The Mask or The Demoiselle d'Ys. The Mask is more "sci-fi", d'Ys is more fantasty.
For a nicely self-contained little horror story with a touch of romance, try The Yellow Sign.
If you like themes of American artists hanging out in Paris, any of the Street / Rue ones will do. Four Winds has the most immediately obvious depth to it though First Shell tells a good war yarn with a touch of insanity.
I found the Repairer of Reputations most the most dissonant/uncomfortable of the tales, especially due to assuming it was written some time in the mid-1900s rather than recognizing it as the futurism it actually represents.
From an LHP perspective, an Alchemist would enjoy The Mask, a Vampire might enjoy the final two stories for their plays on power and identity, an Oneiromancer might either enjoy or get badly skeeved out by The Yellow Sign.
I find they get less blatantly weird after the Repairer of Reputations.
A particularly amusing quest would be to attempt to reconcile the whole set of stories such that there is only one Sylvia, and similarly the other names. I suspect it may be plausible, but have yet to chart it all out.