Anime and Animation:
* "The Legend of Zelda: The Wind Waker" (2002): Ganondorf (voice)
* "Naruto Shippuden" (2007-2017): Gaara (voice)
* "Mobile Suit Gundam Wing" (1995-1996): Heero Yuy (voice)
* "Avatar: The Last Airbender" (2005-2008): The Earth King (voice)
* "The Last Airbender" (2010): The Earth King (voice)
* "Teen Titans" (2003-2006): Slade (voice)
* "Transformers: Animated" (2007-2009): Starscream (voice)
* "Justice League: The Flashpoint Paradox" (2013): Cyborg (voice)
* "Justice League: Throne of Atlantis" (2015): Cyborg (voice)
* "Justice League vs. Teen Titans" (2016): Cyborg (voice)
Video Games:
* "The Legend of Zelda: The Wind Waker" (2002): Ganondorf (voice)
* "Super Smash Bros. Melee" (2001): Ganondorf (voice)
* "Super Smash Bros. Brawl" (2008): Ganondorf (voice)
* "Super Smash Bros. for Nintendo 3DS / Wii U" (2014): Ganondorf (voice)
* "Super Smash Bros. Ultimate" (2018): Ganondorf (voice)
* "Naruto Shippuden: Ultimate Ninja Storm" series (2008-2016): Gaara (voice)
* "Kingdom Hearts" series (2002-2019): Sephiroth (voice)
* "Metal Gear Solid 3: Snake Eater" (2004): The Sorrow (voice)
* "Mass Effect 2" (2010): Legion (voice)
Live-Action:
* "Star Trek: Voyager" (1995-2001): Tuvok (voice)
* "The X-Files" (1993-2002): Various voices
* "The Twilight Zone" (2002-2003): Various voices
This is not an exhaustive list, as Dann Seki has worked on hundreds of projects. He is a highly respected voice actor with a wide range and an impressive resume.
If you're interested in learning more about his work, you can find a complete list of his credits on websites like IMDb.