Sudoku

https://www.websudoku.com/

https://sudoku.com/

Crosswords

https://games.aarp.org/games/daily-crossword

New York Times Word Games & Logic Puzzles

https://help.nytimes.com/hc/en-us/articles/360029050872-Word-Games-and-Logic-Puzzles#SETANDKENKEN

Brain Games (offline)

Scrabble

Chess

Jigsaw Puzzle

Mazes (printouts) https://www.printableparadise.com/printable-mazes.html

More Games (online apps):

Braingle https://www.braingle.com/

Happy Neuron https://www.happy-neuron.com/

Luminosity https://www.lumosity.com/en/