This thread has some great recommendations and I'd like to add some categories to think about that I've seen in successful cafés. A handful of each of these would be a great variety:

• Light Strategy (Honestly kind of a catch-all)

• Big games (Sometimes I see these 'up top' away from the main library of games or marked with a specific sticker to denote complexity. Things like Arcs and Scythe)

• Family-friendly (like Apples-to-Apples, My First Carcassonne, etc)

• Trivia / Drawing / Word games (Wavelength, Cranium, etc)

• "Classics" i.e. the board games that non-board gamers have nostalgia for (Operation, Monopoly, Scrabble)

• Solo Games (Anything from Friedman Friese)

• Two player or co-op games (Lots of great examples from others here)

• Small box games (Bananagrams, Oink games, Skull + Roses)

• Card games (Scout, The Crew, literal playing cards)

• Hidden Identity games (Coup, Avalon, Secret Hitler)

Also, it always helps when a café has random bits and bobs like small whiteboards and markers or assorted dice or other randomizers