>I thought only the US ranks it high
Joyce never even set foot in the United States... You could say this about The Great Gatsby, which US sources might rank in the top 5 compared to 46 in this list.
> "what stuck in your mind"
That's strongly correlated IMHO; and I don't really see any objective metric for the influence of a book anyway.
> He used to hold long book club style readings of his books among the prominent literateur in his times to exactly impinge in their minds that what he writes is clever and not gibberish.
My was so clever, that he had to verbally harangue people into finding his writing clever.
When I don't know, I ask and don't judge (and lacking omniscience, I don't judge anyway).
I'm aware that some think this book is influential, I'm not clear on how widespread that belief is. Also, whether regular readers really like it. And no, Wikipedia does not clear that up.