Film:
* Star Trek: Generations (1994)
* Star Trek: Insurrection (1998)
* Star Trek: Nemesis (2002)
* The Adventures of Pluto Nash (2002)
* I, Robot (2004)
* The Andromeda Strain (2008)
* The Librarian: Quest for the Spear (2004)
* The Librarian: Return to King Solomon's Mines (2006)
* The Librarian: Curse of the Judas Chalice (2008)
* The Day the Earth Stood Still (2008)
* Superman/Batman: Public Enemies (2009) - Voice role
* Star Trek: Of Gods and Men (2010)
* Super 8 (2011)
* The Twilight Saga: Breaking Dawn - Part 2 (2012)
* The Interview (2014)
* The Twilight Saga: Breaking Dawn - Part 2 (2012)
* Avengers: Endgame (2019)
* Star Trek: Picard (2020) - Series regular
* The Nice Guys (2016)
Television:
* Star Trek: The Next Generation (1987-1994)
* Star Trek: Voyager (1995-2001)
* Star Trek: Deep Space Nine (1993-1999)
* Star Trek: Enterprise (2001-2005)
* The Outer Limits (1995-2002)
* The Practice (1997-2004)
* Frasier (2003)
* Numb3rs (2005-2010)
* The Librarian (2004-2008)
* Warehouse 13 (2009-2014)
* The Big Bang Theory (2011-2019)
* Star Trek: Picard (2020-2023)
* The Orville (2017-2022)
This is not an exhaustive list, as he has also appeared in numerous guest roles on other TV shows, and has performed in stage productions.
If you have a specific genre or period you're interested in, let me know and I can give you a more tailored list.