FUTURE PINBALL / BSP Design Software / PC
There have certainly been plenty of video game adaptations of pinball machines, some of them excellent, but Future Pinball is a novel idea that may well please even the most finicky pinball aficionados who can't stand the thought of any kind of digital representation of their analog game.
The game is basically a pinball construction kit, albeit one rendered entirely in 3D, even allowing you to design the outside of the cabinet and look at it from multiple angles. The designers supply only one sci-fi themed table, but there's something like 400 tables out there that fans have made at this point, many of which are accurate representations of classic real-life pinball machines down to the audio clips and sound effects that they used. Players can modify other tables (where the original author allows it) in addition to creating their own from scratch, which aids greatly in learning the initially somewhat confusing layout.
The only real knock against this project is that the loving 3D rendering comes at the price of some very beefy system requirements for a freeware game. A 2 GHz machine with a gigabyte of RAM is the minimum recommendation for smooth play; on my 1.6 GHz laptop with 512 MB it was way too jumpy and frame-skippy to be playable even with the settings toned down as much as possible.