I love monorails for very much the same reason that I love aerial lifts. They are the often the cheapest and quickest way to get a thrill of flying without actually having to get on a plane. But of course, there's reason that more monorails don't exist. I've read so many articles about monorails being expensive to build and maintain and impractical for large numbers of riders, but in Wuppertal, Germany, the Schwebebahn monorail system seems to be an exception. This system reportedly carries up to 80,000 per day and works in conjunction with existing transportation systems like busses to get people around the city.
Amazingly, this system is over 100 years old and seems to be working rather well (it's obvious that the components of this system have been updated over the years).