It's difficult to provide an exhaustive list of all his work, but here are some notable examples:
Movies
* The Lord of the Rings: The Fellowship of the Ring (2001) - Stunt double for Sean Astin
* The Lord of the Rings: The Two Towers (2002) - Stunt double for Sean Astin
* The Lord of the Rings: The Return of the King (2003) - Stunt double for Sean Astin
* The Chronicles of Narnia: The Lion, the Witch and the Wardrobe (2005) - Stunt double for Georgie Henley
* The Chronicles of Narnia: Prince Caspian (2008) - Stunt double for Georgie Henley
* The Chronicles of Narnia: The Voyage of the Dawn Treader (2010) - Stunt double for Georgie Henley
* The Hobbit: An Unexpected Journey (2012) - Stunt performer
* The Hobbit: The Desolation of Smaug (2013) - Stunt performer
* The Hobbit: The Battle of the Five Armies (2014) - Stunt performer
* Avengers: Endgame (2019) - Stunt performer
Television
* Game of Thrones (2011-2019) - Stunt performer
* The Walking Dead (2010-present) - Stunt performer
* Spartacus: Blood and Sand (2010) - Stunt performer
* Vikings (2013-2020) - Stunt performer
* Westworld (2016-present) - Stunt performer
This is just a small sample of the extensive work Ken Ruettgers has done throughout his career. He is a highly respected and accomplished stuntman, known for his dedication and professionalism.