Chainsaw Warrior is science fiction solitaire game from the 1980s, in which you have sixty minutes to save the world. It still appears in the second hand markets.
Golo is a dice game with a Golf theme. It's designed as a casual light game for a few friends, but works perfectly for one.
Ticket to Ride is a multi-player game, it's an award winner and simply a great game. :) Despite being designed for multiple players you can play it on your own, if only you know how.