Based on the Roswell High series of teen literature, Roswell might look like vapid teen nonsense on the outside, but it's a surprisingly clever show set in the town of Roswell, where the mystery surrounding the infamous Roswell incident remains the town's main claim to fame (one which the citizens exploit commercially as much as possible). Amusingly, however, there are strange goings on in Roswell - residents with strange powers, murders and so on, wrapped around plenty of relationship drama to keep it appealing to the teen viewers. After ratings began to wane in season one, UPN toned down the relationship elements and enhanced the sci-fi, which wasn't to the tastes of all viewers. The only blessing is that the writers at least had advance warning that they were going to get cancelled, so we got a sort-of resolution to the story, even if the show felt like it could have continued for many more seasons. It's a fun one to watch in retrospect given the sheer number of famous faces in it (Katherine Heigl, Colin Hanks etc).