While some actors can never get past one major TV role, others have been able to reinvent themselves in some pretty amazing ways.
One actor went from playing a surgeon to a ship captain, while another transformed from a vampire to an FBI agent. Another went from a light-hearted comedic role to a feared anti-hero.
We're talking iconic roles here, so even though several actors are leading some amazing new shows this season, we're leaving those out for now.
Take a look below to see what actors are known for more than one iconic TV role!
Listen, we loved Eric Dane as Mark Sloan (aka McSteamy) on Grey's Anatomy, and we're stil not over his death. But now he's known for a role that we might just love a little more: Tom Chandler on TNT's The Last Ship.
Before Matt Czuchry was known for his role as Cary Agos on The Good Wife, he played an important part of Rory's life as Logan Huntzburger on Gilmore Girls.
Remember when Claire Danes played Angela Chase on My So Called Life? Things have certainly changed. Now, we know her best as CIA Operative Carrie Mathison on Homeland.
This is one heck of a transformation. Before Bryan Cranston was the iconic Walter White on Breaking Bad, he filled a significantly lighter role as Hal on Malcom in the Middle.
Courteney Cox also played two pretty fantastic TV roles. First, she was Monica Geller on Friends, and then she was Jules Cobb on Cougar Town.
We know Johnny Galecki best these days as the very nerdy Leonard Hoftstaedter on The Big Bang Theory. But when he was younger, he was unforgettable as David Healy on Roseanne.
Lauren Graham is pretty amazing at playing a mom on TV. She followed her iconic role as Lorelai Gilmore with another fabulous mom role, Sarah Braverman on Parenthood. Now, she's going full circle, and we'll see her as Lorelai Gilmore again on the revival series!
Before Alyson Hannigan was Lily Aldrin on How I Met Your Mother, she was a brainy witch who helped save the world more than a few times on Buffy the Vampire Slayer. As a bonus, How I Met Your Mother gave a few subtle shoutouts to Evil Willow during its run.
Michael J. Fox
Michael J. Fox has graced our TV screens for a long time. We knew him first as Alex on Family Ties, then many years later as Mike Flaherty on Spin City followed by Mike Henry on The Michael J. Fox Show. Most recently, he was Louis Canning on The Good Wife. (And I know, I know. There's also Back to the Future. But we're focused on TV here.)
Before Mayim Bialik played a genuis scientist on The Big Bang Theory (and before she become one in real life) she was unforgettable as Blossom Russo.
David Boreanaz has played two major TV roles on long-running series. We know him now as Seeley Booth on Bones, but years ago, he was a vampire with a soul on Buffy the Vampire Slayer and then its spinoff, Angel.
Alyssa Milano was adorable as Samantha on the classic sitcom, Who's the Boss? She went on to play a very different role as Phoebe Halliwell on Charmed. Most recently, she played another pretty significant role as Savi on ABC's Mistresses.
Matthew Fox has also played two iconic TV roles. First, he was Charlie Salinger on Party of Five, and then he won us over once again as Jack Shepherd on Lost.
Before Julianne Margulies was the incredible Alicia Florrick on The Good Wife, she spent years playing the iconic role of Carol Hathaway on ER.
Neil Patrick Harris
Neil Patrick Harris has come a long way, hasn't he? As a young child, he played an adorable doctor on Doogie Howser, M.D. Years later, we knew him as.... wait for it... Barney Stinson on How I Met Your Mother!
Yet another actor from Gilmore Girls, Jared Padalecki was known first as Rory's first boyfriend, Dean. Now, he's kicking some major demon butt on a regular basis as Sam Winchester on Supernatural.
Oh man, who can forget about Married with Children? Before Ed O'Neil was Jay Pritchett on Modern Family, he was the not-so-likeable show salesman, Al Bundy.
Firefly may have only lasted one season, but the cult classic gave us an iconic TV character in Malcom Reynolds, played by Nathan Fillion. Later, Fillion become known for his role as Richard Castle on Castle.
Emmy winning Julia Louis-Dreyfus is a force to be reckoned with. We knew her first as Elaine Benes on Seinfeld, and now she graces our screens as Selina Meyer on HBO's Veep.