I always thought the first season was amazing, but went steeply downhill from there. One of those times the writers had not thought things through and got sort of lost along the way. In fact, along with Twin Peaks, Heroes is the fastest decline I’ve seen in a show.
Anyway, they did expect to be renewed one more time. Their cancellation was considered more or less about 70% chance to survive, 30% chance to sink.
You might want to consider the british Misfits.Trailer.
People gain super, or not-so-super powers (I think my fave is the ability to control milk) after a mysterious storm. The series centres around five teenage offenders doing community service.
WARNING - contains gloriously foul language and a lot of shagging.
Do not watch with parents or children in the room.
I just started the final season. I have enjoyed the show, especially the first season. Some of the things the people in charge of the show did made me scratch my head and roll my eyes, but I still found it overall enjoyable.
The show never hooked me like Lost did, so it didn’t bother me too much when the show started going off in weird directions.