Cree Summer Francks

Though she's known to the general public as the flighty Winifred "Freddie" Brooks on A Different World, Cree is one of the busiest voice actors in animation!
Beginning as the voice of Penny in the original Inspector Gadget series in the early 1980s, she's worked non-stop behind the camera, which is a shame, because she's a real babe!
Note: to keep the list manageable, I've only listed animation work either based on comic / pulp characters (like Superman or Conan) or with heavy sci-fi / fantasy elements (like Danny Phantom)
Trivia:
Her full name is Cree Summer Francks. Her brother is Rainbow Sun Francks, a regular on Stargate: Atlantis as Lt. Aiden Ford. He also appeared in Alien vs Predator: Requiem!
In the first season Drawn Together DVD commentary she stated that she was hired to do the voice of Meg Griffin on Family Guy, but was fired because she sounded "too black". (????)

Among her many, many genre appearances include...
Conan: Red Nails (Valeria of the Red Brotherhood)
SuperHero Squad Show / SuperHero Squad[VG] (Storm)
Batman: The Brave and the Bold (Vixen)
Star Wars: the Clone Wars [2004] ( Luminara Unduli)
Spectacular Spider-Man (Glory Grant)
Batman Beyond (Max Gibson)
Transformers: Animated (Blackarachnia)
Fantastic Four: the Movie [VG] (Alicia Masters)
Drawn Together / Drawn Together: the Movie
(Foxxy Love aka Georgina Georgiopolis)
Turok: Son of Stone (Sepinto)
X-Men: Legends [VG] (Magma)
Superman: DoomsDay(Mercy Graves)
My Life as a TeenAge Robot (Tiff Krust)
Hellboy: Blood & Iron (Hecate)
W.I.T.C.H. (Ember)
BEN 10 (FrightWig)
Danny Phantom (Valerie Gray)
Atlantis: the Lost Empire/ Milo's Return/ Search for the Journal [VG]
(Princess "Kida" Kidagakash)
Sabrina: the Animated Series (Chloe)
Superman: the Animated Series "Heavy Metal" (Natasha)
Incredible Hulk [1997] (Greena)
Spider-Man (Professor Jolenna Williams)
Mortal Kombat: Defenders of the Realm (Princess Kitana)
Gargoyles (Hyena)
Slimer & the Real GhostBusters (Chilly Cooper)
Ewoks (Princess Kneesaa)
Inspector Gadget [1983-84] (Penny)

Check out...
Cree's Voice Chasers credits page

Other actresses to play Princess Kitana:
Talisa Soto in Mortal Kombat / Mortal Kombat: Annihilation
Note: two actresses played Kitana in the Mortal Kombat: Conquest tv series--Dara Tomanovich & Audie England

Other actresses to play Luminara Unduli:
Olivia D'Abo in Star Wars: The Clone Wars (2009)/ Star Wars: the Clone Wars "Republic Heroes" [VG]
Fay David in Star Wars III: Revenge of the Sith

Other actresses to play Storm:
Halle Berry in X-Men / X-Men 2 / X-Men: the Last Stand
Susan Dalian in Wolverine and the X-Men
Kirsten Williamson in X-Men: Evolution
Alison Sealy-Smith in Spider-Man, X-Men [Replaced Iona Morris]
Iona Morris in Spider-Man, X-Men
Andi Chapman in X-Men "Pryde of the X-Men" [pilot]
I'm not sure who did Storm / Ororo Munroe in Spider-Man and His Amazing Friends eps "A Firestar Is Born", "The Education of a Superhero" and "The X-Men Adventure"
Storm /Ororo Munroe voice actresses in videogames include Dawnn Lewis, Debra Wilson, Tangie Ambrose, Alison Sealy-Smith, Cheryl Carter, Catherine Disher,

Other actresses to play Vixen:
Gina Torres in Justice League Unlimited

Other actresses to play Glory Grant:
Nell Carter in Spider-Man [1997]

Other actresses to play Blackarachina:
Venus Terzo in Beast Machines: Transformers / Beast Wars: Transformers

Other actresses to play Mercy Graves:
Gwendoline Yeo in The Batman
Lisa Edelstein in Justice League / Justice League Unlimited / Superman the Animated Series / Superman & Batman: World's Finest
Tara Strong in Superman: Brainiac Attacks

Other actresses to play Alicia Masters...
Kerry Washington in Fantastic Four: the Movie / Fantastic Four: Rise of the Silver Surfer
Sunita Prasad in Fantastic Four: World's Greatest Heroes
Paulina Lomas in Marvel Action Hour: Fantastic Four
Kat Green in The Fantastic Four [1994] [live-action film, never officially released]

Other actresses to play Penny:
Tegan Moss in Inspector Gadget's Biggest Caper Ever / Gadget & the Gadgetinis
Caitlin Wachs in Inspector Gadget 2
Michelle Trachtenberg in Inspector Gadget [1999]
Holly Berger in Inspector Gadget: Season 2