voice actors L
Voiceover artist on countless movie trailers, TV ads, etc. Parodied himself in plenty of things, as well. Announcer on Fillmore!, etc.
Father on Codename: Kids Next Door; Jeremy Hawke, Orson Welles, et al. on The Critic; Red Tornado on DC Super Hero Girls; Simion, et al. on Dexter's Lab; Longhorn, et al. on Freakazoid!; Kif, Morbo, Calculon, et al. on Futurama; Chief Quimby on Inspector Gadget; Chancellor Neighsay on My Little Pony: Friendship Is Magic; the Brain on Pinky & the Brain; Tapper in Ralph Breaks the Internet; Magneto on Super Hero Squad Show; Alec Baldwin in Team America: World Police; the Fin and the Deadly Bulb on The Tick; Gus on Tripping the Rift; Master Fung in later seasons of Xiaolin Showdown; Mr. Big in Zootopia; and lots of other stuff too...
LaMarr, Phil See actors L
Duo in The Animatrix; The Earth King on Avatar: The Last Airbender; JARVIS et al. on Avengers: Earth's Mightiest Heroes; Lucius Fox and Killer Moth on DC Super Hero Girls (Dog Magnus in Intergalactic Games); Wilt on Foster's Home For Imaginary Friends; Hermes, Preacherbot, et al. on Futurama; Wood in Hoodwinked Too!; Green Lantern on Justice League; Gabe, Carny, Aqua Seneschal, et al. on Kaijudo; Ozzy on Ozzy & Drix; the title character on Samurai Jack; Randy and Robbie Robertson on The Spectacular Spider-Man; Bail Organa, Kit Fisto, et al. on Star Wars: The Clone Wars; Virgil/Static on Static Shock; Jazz on Transformers Animated; Gambit on Wolverine and the X-Men; etc...
Landau, Juliet See actresses L
Verdona, Lili Tennyson, et al. on Ben 10: Alien Force, Tala et al. on Justice League Unlimited.
Lander, David L. See actors L
Milo on Galaxy High School, Doc Boy in A Garfield Christmas, Da Shrimp on The Little Mermaid, a Filth in an episode of The Tick, a weasel in Who Framed Roger Rabbit, maybe some other stuff...
Lane, Nathan See actors L
Hamegg in the 2009 Astro Boy; Timon in The Lion King; Preed in Titan A.E..
Lansbury, Angela See actresses L
Clayface, Metallo, Mayor Hill on The Batman; title character on Blue Dragon; Rick Flag in Justice League: The New Frontier; Goemon on Lupin the 3rd; Alan on MÄR; Hayate Gekko et al. on Naruto; Sanosuke on Rurouni Kenshin; Kimishima on s-CRY-ed; etc.
Dowager Empress Marie in Anastasia; Mrs. Potts in Beauty and the Beast; Mayor McGerkle in The Grinch; Mommy Fortuna in The Last Unicorn.
La Placa, Alison See actresses L
Baby Doll in an episode of Batman: The Animated Series.
Lee, Christopher See actors L
The Jabberwocky in Alice in Wonderland; Death in The Colour of Magic; Pastor Galswells in Corpse Bride; King Haggard in The Last Unicorn; Count Dooku in Star Wars: The Clone Wars; etc.
Angel on Big O; Tatsuki, Ururu, Yoruichi (human form), et al. on Bleach; Faye Valentine on Cowboy Bebop; Dorothy on MÄR; Sonia Sky on Megaman Star Force; Kiva on Megas XLR; Haruhi on The Melancholy of Haruhi Suzumiya; Chris on Mobile Suit Gundam 0080; Batch and Ms. Loon on Mon Colle Knights; Moegi et al. on Naruto; Kagero in Ninja Scroll; Twilight Suzuka on Outlaw Star; Rumi in Perfect Blue; Kachiro and Shiba on The Prince of Tennis; Yahiko on Rurouni Kenshin; Kiyone on Tenchi in Tokyo; Sprocket on Viewtiful Joe; etc.
Mai on Avatar: The Last Airbender.
Honker on Darkwing Duck; Sheila on Dungeons & Dragons; Rowlf on Muppet Babies; Alex on Totally Spies!; Captain Blue Jr. on Viewtiful Joe; etc.
Lewis, Vicki See actresses L
Star Sapphire and Wonder Woman on Batman: The Brave and the Bold; Serena on Ben 10: Alien Force; Iris West in Justice League: The New Frontier; Posey on Mission Hill; Persephone in Wonder Woman.
Lien, Jennifer See actresses L
Mileina Vashti on Gundam 00; Pinkie Pie, Fluttershy, et al. on My Little Pony: Friendship Is Magic; etc.
Valerie Fox in the first episode of The Critic, Elle on Men in Black. She was also on at least one of Adam Sandler's CDs...
Liu, Lucy See actresses L
Hela on Cubix; Boo on Now and Then, Here and There; Misty and Jessie on Pokemon (seasons 1-8); etc.
Sio in Afro Samurai: Resurrection; herself (or at least her head) on Futurama; adult Jade in an ep of Jackie Chan Adventures; Viper in the Kung Fu Panda movies (and series); Conformity in Michael Jackson's Halloween; bandit leader in Star Wars: Visions; Callisto in Strange World; Silvermist in the Tinker Bell movies; etc.
Lovitz, Jon See actors L
Chula in An American Tail: Fievel Goes West; Jay Sherman on The Critic; Quasimodo in Hotel Transylvania; the original voice of Red in M&M commercials (replaced by Billy West); Artie Ziff et al. on The Simpsons.
Brak's Dad on The Brak Show, Space Ghost on Cartoon Planet and Space Ghost: Coast to Coast, etc.
Jinno on Afro Samurai; Robin and Red Hood in Batman Ninja; Red Robin in Batman Unlimited; Ben on Ben 10: Alien Force (and subsequent series); Keigo et al. on Bleach; Shu on Blue Dragon; Suzaku on Code Geass; Sena on Eyeshield 21; Simon on Gurren Lagann; Superman on Legion of Super Heroes; Alviss on MÄR; Zack on Megaman Star Force; Karl Neumann on Monster; Sasuke on Naruto; Yuu on Noein; Haru on Rave Master; Iceman on Wolverine and the X-Men; etc. Also he appears as himself (live-action) on Titansgrave. And I saw him in a live-action role in a short film, In a Foreign Town.
Lucas, David See Blum, Steve
Martian Manhunter on Justice League and in Justice League: Doom. I suppose I've seen him in some live-action stuff, but I don't remember it that well. Maybe someday I'll move his entry, but for now I'll leave it here.