If you are unfamiliar with the 'Firefly' series, it is definitely worth your time/money.
Witty dialogue and interesting characters combined with a space/cowboy/new frontier-flavor make for interesting viewing. Don't forget there was also the movie 'Serenity' with the same cast...
Do NOT buy Firefly or ever watch it. It will just make you angry and hateful towards Fox for how bad they screwed up in debuting the show on tv and then canceling it!!! *rawr*