The process of launching a television show is a very risky and expensive venture. Once things like lighting, sound, editing and everything in between are taken into account, it's not unheard of for the cost to exceed a million dollars per episode with no guarantee you'll ever see that investment again. And even with the best script or the flashiest CGI money can buy, the show's success is still heavily dependent on the strength of its characters and the actors who play them. This is the power of casting.Producers and casting directors are responsible for finding someone who can embody a certain persona for what could be several years whilst consistently appealing to their intended audience, and once they've made their final decision there's no going back. As for the viewer, there are three typical behaviours the average person displays when browsing the cast list for a new show.The first is the nod of approval, usually for an actor they've seen or heard of before and have confidence in their ability to pull the role off. The second is the look of anticipation for someone they've never seen act but have probably heard good things about. This article focuses on the last one, the type of casting that leaves a face of intrigue or bewilderment on the reader because they, for whatever reason, cannot fathom the idea of them playing this sort of role on that type of show. Most of the actors in this list were unlikely to be first choice for casting, some may even have been expected to fail in their role, but every single one of them by luck or design have turned out to be an awesome choice and have had more than a positive impact on their respective shows. As per every discussion about television, this article is on red alert for SPOILERS and the list is in no particular order.