Picking the greatest Porsches is like splitting hairs. All of them are excellent on some level. But some have become legendary, and a handful of modern models are destined to become classics. With the help of Dave Engleman, media relations manager for Porsche in North America, we have highlighted 25 models for their impact on the company, on racing, and on the history of the automobile. We ranked 10 race cars, followed by 15 road cars, rather than mix apples with oranges. We did not consider cars from tuners like RUF, nor ones still under development, such as the 918 Spyder. The latest 911 looks like a winner, but it's not ranked either, because it was just released, and it has to prove itself over the long haul. As hard as we tried to be circumspect and all-inclusive, this list will certainly spark debate. We welcome it.