So I thought it would be kind of neat to see what other movies or shows that people have seen the HP cast in. Before and since the movies. That doesn't mean their first and last movie they'd starred in. Just which order you've viewed their work.

Dan Radcliff - Harry Potter // My Boy Jack
Emma Watson - Harry Potter // Noah
Rupert Grint - Harry Potter // Driving Lessons
Richard Harris - Abraham // Camelot
Maggie Smith - Clash of the Titans (1981) // Hook
Robbie Coltrane - Alice in Wonderland // Alex Rider Operation Stormbreaker
Michael Gambon - Squanto A Warriors Tale // The Hollow Crown (Henry the VI)
Bonnie Wright - Harry Potter // The Philosophers (also known as After the Dark)
Julie Walters - Harry Potter// The Hollow Crown (Henry the IV, V)
Mark Williams - Red Dwarf // Doctor Who (The Power of Three)
Tom Felton - The Borrowers // Anna and the King
Alan Rickman - Die Hard // Something the Lord Made
Ralph Fiennes - Maid in Manhattan // Wrath of the Titans
Jason Isaacs - Highlander (The Lady and the Tiger)// The State Within
Helena Bonham Carter - Merlin (1998) // Les Miserables
Natalia Tena - About a Boy // Game of Thrones
David Thewlis - Dragonheart // War Horse
Gary Oldman - JFK //Dawn of the Planet of the Apes
Timothy Spall - Red Dwarf // Sweeney Todd
John Hurt - Spaceballs // Hercules (2014)
Richard Griffiths - Superman II // The Hollow Crown (Henry the V)
Warwick Davis - Ewoks: Battle for Endor // Prince Caspian (1989)
Harry Melling - Harry Potter // Merlin (The Sorcerer's Shadow)
Brendan Gleeson - Braveheart // Albert Nobbs
John Cleese - The Jungle Book (1994)// Fierce Creatures
David Tennant - Blackpool // Glorius 39
Rhys Ivans - Notting Hill // Anonymous
Bill Nighy - The Lost Prince // Pirates of the Caribbean At World's End
Emma Thompson - Sense and Sensability // Saving Mr. Banks
Kenneth Branagh - Wild Wild West // Five Children and It
David Bradley - Harry Potter // Game of Thrones

My list may be incomplete but that is because I haven't seen anyone else that I can remember in anything since the potter franchise or before. Feel free to use add or use as little as you can recall.