Sometimes, you know exactly what you're going to get from a TV performance, and they deliver: when Michael Scott stepped into The Office, we knew we were going to get a hilarious performance. When Julia-Louis Dreyfus was cast in Veep, likewise, we knew the results would be side-splittingly funny. Or that when HBO's Big Little Lies had a cast including Reese Witherspoon, Nicole Kidman, Laura Dern, and Alexander Skarsgard, the results would be pretty spectacular.
Casting, especially now, plays a huge part in generating hype for a TV show. Series are often built around actors, with it no longer noteworthy when an A-list movie star takes on a TV role. The lines have been blurred so much.
But still, across TV history there have been castings that people DIDN'T expect to be good. Just like how everyone doubted Michael Keaton in Batman, or Heath Leader in The Dark Knight, there are casting decisions that generate controversy and derision, or at the very least a healthy dose of scepticism. Whether it's because the person has always been typecast, or only really been in one thing, or hasn't shown anything special, there are some TV performances that have come almost out of nowhere and defied all expectations.