For me it was Battleship Solitaire (https://lukerissacher.com/battleships), which I found via hackernews. For the first few weeks I played it every day at every opportunity, and since then I fire it up at least every couple days and burn through it. Its a less involved Sudoku logic puzzle that is mind-bogglingly satisfying to complete.
bombcar|1 year ago
joquarky|1 year ago
ronyeh|1 year ago
rc5150|1 year ago