Am exactly the same as you, OP. Feel as if I have read them all! And I don't like American crime much.
Here's a list of (some) of my favourite authors - maybe you haven't read some of them?
Susan Hill - Simon Serrralier series
Donn Leone - Brunetti series, set in Venice. The earlier ones are the beat.
Barbara Nadel - have only read her Inspector Ikmen series, set in Istanbul, but she has another series set in East End of London (which I tried & didn't like as much).
Arnaldur Indridason - Scandi crime, very good.
Harry Bingham - DI Fiona Griffiths series - have read the first 3 & am waiting for the fourth to come down in price a bit.
Ian Rankin - am sure you have read him, but have to put him on a favourites list.
Alex Gray - Set in Glasgown with Inspector Lorimer. Not as good as some of the above but not bad at all!
Would love to hear back if you can recommend any!