Color Junction is a relatively easy game that you can lose in less than 2 minutes. I just wish the game would give me kudos on the rare occasions when I win!
Sudoku is an awfully addictive game that I don’t play. There is a decent web version if you click the logo but a Google version is here for my daughter.
X-Plane is not a game - it’s a flight training simulator that takes a lot of study. I love it. You can learn to fly solo or you can fly with others over the network. You can fly anything from a Cessna to a 747. You can even learn to fly the Space Shuttle (from orbit back to Earth. And you can try to fly around Mars, which of course is awfully difficult because of the low gravity. Amazing work. You can get add-ons at X-plane.org, and they have a thriving community. For me, it’s a lot of fun landing a 737 at Washington National (KDCA).
My favorite Mahjong game at the moment is Mahjong Forests. Another late night addiction. Highly recommended for insomniacs.
.