Here are some ideas for different combinations of Europa Editions books, for your Europa Challenge perusal.
Favorite First Europas:
The Elegance of the Hedgehog, by Muriel Barbery
My Brilliant Friend, by Elena Ferrante
Old Filth, by Jane Gardam
Series:
Jane Gardam's Old Filth trilogy, including Old Filth, The Man in the Wooden Hat, and Last Friends (literary fiction, British)
Elena Ferrante's Neapolitan Novels: My Brilliant Friend, The Story of a New Name, Those Who Leave and Those Who Stay (literary fiction, Italian)
Stav Sherez: A Dark Redemption, Eleven Days (World Noir, British)
Philippe Georget: Summertime, All the Cats Are Bored; Autumn, All the Cats Return (World Noir, French)
Jean-Claude Izzo's Marseilles Trilogy (World Noir, French)
World Noir:
Amara Lakhous's comic noirs like Divorce Islamic Style or Clash of Civilizations Over an Elevator in Piazza Vittorio
Maurizio de Giovanni's Commissario Ricciardo series, starting with I Will Have Vengeance
Caryl Ferey's dark noirs like Zulu and Utu, set in South Africa and New Zealand, respectively
Massimo Carlotto's standalones like Death's Dark Abyss or series like the Giorgio Pellegrini books (The Goodbye Kiss and At the End of a Dull Day)
Minotaur, by Benjamin Tammuz
Americans:
Falling to Earth, by Kate Southworth
You Deserve Nothing, by Alexander Maksik
The Angry Buddhist, by Seth Greenland
Treasure Island!!!, by Sara Levine
These Dreams of You, by Steve Erickson
Historical Fiction:
Pure, by Andrew Miller (French Revolution)
The Eyes of Venice, by Alessandro Barbero (Medici Italy)
Red Joan, by Jennie Rooney (20th century Cold War)
The Palestinian Lover, by Selim Nassib (early 20th century Israel/Palestine)
Saving Mozart, by Raphael Jerusalmy (World War 2, Holocaust)
Lovers, by Daniel Arsand (pre-Revolutionary France, also LGBT)
The Nun, by Simonetta Agnello Hornby (Sicily, Risorgimento)
Comedy:
I Hadn't Understood and My Mother-in-Law Drinks, by Diego de Silva (also World Noir)
Amara Lakhous's books, see above
Lazarus is Dead, by Richard Beard
Get Me Out of Here, by Henry Sutton
Game for Five and Three-Card Monte, by Marco Malvaldi (also World Noir)
Political & Social Issues:
Moffie, by Andre Carl van der Merwe (LGBT)
Take This Man, by Alice Zeniter (Immigration, interracial marriage)
Just Call Me Superhero, by Alina Bronsky (Disability, discrimination)
The Proof of the Honey, by Salwa al Neimi (Sex in the Arabic world)
Time Present and Time Past, by Deirdre Madden (Economic collapse of Ireland, modern family life)
YA-Friendly Crossovers (Europa doesn't publish a YA line but these books would appeal to the adult YA reader):
A Long Way From Verona, by Jane Gardam
Everything Happens Today, by Jesse Browner
Take This Man, by Alice Zeniter
You Deserve Nothing, by Alexander Maksik
Margherita Dolce Vita, by Stefano Benni (also comedy)
...these are only a few ideas. Europa Editions publishes so many great books, you won't have any trouble finding a few that you'll enjoy. Happy reading!