I haven't played it yet, but after watching hours of Desert Bus (Sega CD), I'm tempted to say that's one of the most boring games ever made.
An HD remake was very recently released on the mobile platform (iOS and Android) and I'm kind of curious to give it a spin
For those not familiar with Desert Bus, I'll give an explanation of it:
You drive a coach bus from Tuscon to Las Vegas and back. Your bus caps at 45mph, and the journey takes roughly 8 hours to complete, one way. Each time you reach a destination you receive a point.
The road is perfectly straight and there is no traffic. The challenge of the game, however, lies in the fact that the wheel doesn't rest at a neutral heading and has a slight list to the right, so if you don't correct the wheel every few seconds or so, the bus will go off the road and crash. If you crash, you're towed back to the start in real time. So if you crashed six hours into the trip, it takes six more before you can start playing again.
If you stop the bus for long enough, it will over-heat and break down. Same towing rules apply.
The start button honks the horn. There is no pause button. To score a point, you must play this game for eight hours straight.