voice actors M-N
Stan Smith and Roger on American Dad!; Tim the Bear on The Cleveland Show; Peter, Stewie, Brian, Quagmire, Tom Tucker, et al. on Family Guy. He's also done some live-action acting, as well as writing/producing/directing.
Dot, et al. on Animaniacs; Avatar Yangchen and Hama in episodes of Avatar: The Last Airbender; Antonia Chillingsworth in Dark Fury; Fang on Dave the Barbarian; Mom, Linda the news anchor, et al. on Futurama; Osono in Kiki's Delivery Service; Obaba in Nausicaa of the Valley of the Wind; Sarah Ravencroft in Scooby-Doo and the Witch's Ghost; Agnes Skinner, et al. on The Simpsons; Babs on Tiny Toon Adventures; Queen Victoria (elderly) in Van Helsing: The London Assignment; etc.
Madsen, Virginia See actresses M
Roulette and Dr. Sarah Corwin on Justice League; Hippolyta in Wonder Woman; etc.
Mako (aka Makoto Iwamatsu)
Malick, Wendie See actresses M
Iroh on Avatar: The Last Airbender; main title narrator on Dexter's Laboratory; Aku on Samurai Jack; Achoo in an episode of Duck Dodgers that parodied Samurai Jack; Splinter in TMNT. I also saw him in a live-action role in an episode of Greatest American Hero.
Chicha in The Emperor's New Groove franchise; Principal Folsom on Fillmore!; Eda on The Owl House; etc.
Marin, Cheech See actors M
Ramone in Cars; Mad Hog in Hoodwinked Too!; Banzai in The Lion King; Tito in Oliver & Company; Lencho on Santo Bugito; himself in an episode of The Simpsons; etc.
Firefly on The Batman; Speedy and Paco on Batman: The Brave and the Bold; Duke on G.I. Joe: Renegades; Max in A Goofy Movie; Binx in Hocus Pocus; Fingers on Kaijudo; Danger Duck on Loonatics Unleashed; Haku in Spirited Away; Richie on Static Shock; Billy Numerous in a couple eps of Teen Titans; Tino on The Weekenders; Matt on W.I.T.C.H.; Chase Young on Xiaolin Showdown; etc. I also know him from some live-action stuff, such as Almost Home, but mainly I know him as a voice actor, which is why I'm putting his links here.
Black Widow, et al. on The Avengers: Earth's Mightiest Heroes; Irwin, et al. on The Grim Adventures of Billy & Mandy; Wonder Woman in Justice League: Crisis on Two Earths; Mary Jane, et al. on The Spectacular Spider-Man; Hera Syndulla, et al. on Star Wars Rebels (and Star Wars: Forces of Destiny); Tiffany, Kristin, et al. on Sym-Bionic Titan; Black Canary, et al. on Young Justice; etc.
McBrayer, Jack See actors M
Villain-Tine in an episode of The Awesomes; Mr. Chicken Chickenslice in an episode of Axe Cop; Irving on Phineas & Ferb; Fix-It Felix in Wreck-It Ralph, etc.
McDowell, Malcolm See actors M
Schwartzwald on The Big O, Chojiro Sasakibe, Ryuken Ishida, Kurodo, et al. on Bleach, the Narrator on Bobobo-bo Bo-bobo, Charles zi Britannia on Code Geass, Captain Jurgens on Eureka Seven, Babbo on MÄR, Ramba Ral on Mobile Suit Gundam, Dr. Boyer, Franz Bonaparta on Monster, etc.
Dr. Calico in Bolt; Merlyn in DC Showcase: Green Arrow; Vater Orlaag on Metalocalypse; Reginald Fletcher on Phineas and Ferb; Metallo on Superman; Mad Mod on Teen Titans; Commodore Tolwyn on Wing Commander Academy; etc.
McGlynn, Mary Elizabeth
George Kaminski et al. on Case Closed; Master Roshi, et al. on Dragon Ball; Jean Havoc on Fullmetal Alchemist; Buggy the Clown et al. on One Piece (FUNi dub); Shota Jinnouichi in Summer Wars; Cain Nightroad on Trinity Blood; etc.
Cornelia li Britannia on Code Geass, Julia on Cowboy Bebop, Mischa and Maurice on Eureka Seven, Motoko Kusanagi on Ghost in the Shell: Stand Alone Complex, Aihi on Kekkaishi, Kurenai et al. on Naruto (and Naruto Shippuden), Hilda on Outlaw Star, Jagura on Wolf's Rain, etc.
Bato on Avatar: The Last Airbender; Four Arms on Ben 10; I.Q. Hi et al. on Duck Dodgers; Abin Sur in Green Lantern: First Flight; General Grievous and Kit Fisto in the microseries Star Wars: Clone Wars (volume 2); Lance's father et al. on Sym-Bionic Titan; etc. And I must have seen some of his live-action work, though I'm afraid I don't remember any of it.
Hohenheim on Fullmetal Alchemist; Colonel Geist in Ghost Patrol; Duo Maxwell on Gundam Wing; Ali Al-Saachez on Gundam 00; the govlins in Howard Lovecraft and the Frozen Kingdom; Koga on InuYasha; Ace and Ignatius on Krypto the Superdog; GutsMan et al. on MegaMan NT Warrior; Flam, et al. on My Little Pony: Friendship Is Magic; Wolverine on X-Men: Evolution; etc.
Various guest voices on Avatar: The Last Airbender; J.T. on Ben 10: Alien Force; Kevin on Mission Hill; a small role in ParaNorman; Francis on The Secret Saturdays; Quicksilver on Superhero Squad Show; Robin on Teen Titans; Black in Tekkonkinkreet; etc.
Oglethorpe on Aqua Teen Hunger Force, Brak on The Brak Show and Cartoon Planet and occasionally Space Ghost: Coast to coast, etc.
Metcalf, Laurie See actresses Md-Mz
Donna Alman on God, the Devil and Bob; Andy's mom in the Toy Story movies; Sarah Hawkins in Treasure Planet; etc.
Miller, Lara Jill
Min and Lulu on Blood+, a Tachikoma on Ghost in the Shell: Stand Alone Complex, the title character on The Life and Times of Juniper Lee, Haul on Rave Master, Scheris Adjani on s-CRY-ed, Koko on Zatch Bell!, etc.
Astro on Astro Boy; Lonette in Cool World; Dexter in seasons 3-4 of Dexter's Lab; Madame Foster et al. on Foster's Home For Imaginary Friends; Ophelia on The Life and Times of Juniper Lee; Zadavia et al. on Loonatics Unleashed; The Flea et al. on Mucha Lucha; Mrs. Wakeman on My Life as a Teenage Robot; Crystal in Scooby-Doo and the Alien Invaders; Irma on W.I.T.C.H.; etc.
Mirren, Helen See actresses Md-Mz
Deep Thought in The Hitchhiker's Guide to the Galaxy; Dean Hardscrabble in Monsters University; Nyra in The Owls of Ga'Hoole; Tuya in The Prince of Egypt.
Montalban, Ricardo See actors M
Head of Council in The Ant Bully; Guitierrez on Freakazoid!; Señor Senior Sr. on Kim Possible.
Morris, Phil See actors M
Bud in All I Want for Christmas Is You; Joshua Sweet in Atlantis: The Lost Empire; Damon Gray on Danny Phantom; Vandal Savage on Justice League and in Jusice League: Doom; King Faraday in Justice League: The New Frontier; Imperiex on Legion of Super Heroes; Doc Saturday et al. on The Secret Saturdays; etc.
Goku on Dragon Ball Z, Trowa Barton on Gundam Wing, Billy Katagiri on Gundam 00, Miroku on InuYasha, the title character in Mosaic, Prince Aika on Oban Star-Racers, Cyclops/Scott Summers on X-Men: Evolution, etc.
Garfield in all kinds of specials plus the series Garfield & Friends, Peter Venkman on The Real Ghostbusters, and Larry the Crash Test Dummy in a series of PSAs.
Napier, Charles See actors N-O
Duke Phillips on The Critic; Zed on Men in Black: The Series; General Hardcastle on Superman and Justice League; etc.
Newbern, George See actors N-O
Frank Tennyson on Ben 10: Alien Force; Sephiroth in Final Fantasy VII: Advent Children; Superman on Justice League.
Norris, Daran See actors N-O
Count Spankulot on Codename: Kids Next Door; Cowboy Andy et al. on Cowboy Bebop; Vincent in Cowboy Bebop: The Movie; Cosmo, Mr. Turner, et al. on The Fairly Oddparents; J. Jonah Jameson on The Spectacular Spider-Man; various voices on Star Wars: Clone Wars; Spottswoode in Team America: World Police; etc.