There is one thing that separates Cash Cab from the countless other game shows a person could watch. There is one singular difference that makes this show, about one man asking a group of contestants general-knowledge trivia questions, better than most others, and that is the premise.
The host drives around in an ordinary-looking cab in New York. The passengers that he picks up become the contestants. They answer general-knowledge questions all the way to their destination. If they miss three questions, though, they're kicked out and win nothing.
Nobody has prior knowledge that they are going to be on the show. Nobody has time to study or prepare for this. You may have one person, or a group, and this depends entirely on what they, as a person, know as part of their every-day knowledge. You can get a group of people who get three strikes right away, or you could get an individual who wins some obscene amount of money and then doubles it on the video-bonus question. Or you could get any mixture of the two. You never know, they never know, and that what makes this show great.
The show is not without it's faults. The host can be annoying at times, trying to be funny. And the melodrama is entirely over-blown. You have to wait an obscene amount of time before he confirms the question. After a while, it really begins to weigh the show down.
Still, Cash Cab is very much like a box of chocolates. You can get a bright bulb as much as you get a complete dud. But, no matter what, that's still good chocolate... I mean viewing.