Wow, amazing, so it appears that the guy who played Grodin on Atlantis is married to Erin Chambers sister and Erin played Sora on Atlantis.
Erin Chambers also did a voicing for numerous Hayao Miyazaki animes such as: The Cat Returns, My Neighbors the Yamadas, and Whisper of the Heart. The first thing I saw her in was a Disney movie called Don't Look Under The Bed.
It appears Claudia Black, Vala, had done numerous voicings for games and movies such as Neopets: The Darkest Faerie, God of War, Lords of Everquest, and for the anime Steel Angel Kurumi.
Ben Browder did voicings for the cartoon Justice League.
The actor who played Halling in Atlantis played a different character years earlier on SG-1 called Pallan.
Colm Meaney who played as one of the Genii, Cowen, was previously on Star Trek: Deep Space Nine and Star Trek: The Next Generation. He was also on an episode of MacGyver, where Richard Dean Anderson (Jack O'Neill) was the star of the show.
Captain Dave Kleinman played by Kirby Morrow is one of the best anime voice actors ever!! He's done: Transformers, InuYasha, Gundam Seed Destiny, Mobile Suit Gundam: Char's Counterattack, Dragonball Z, Hamtaro, Escaflowne, Gundam Wing, Infinite Ryvius, Melty Lancer, Mobile Suit Gundam: Encounters in Space, X-Men: Evolution, Ys: The Ark of Napishtim, Gundam: Battle Assault 2, Hikaru no go, Rockman.exe, Project ARMS, The Daichis: Earth's Defense Family, Star Ocean EX, Broken Saints, Mobile Suit Gundam Wing: The Movie - Endless Waltz, CardCaptors, Kessen, Yvon of the Yukon, Ninja Turtles: The Next Mutation, and Ranma 1/2 which Teryl Rothery (Janet Frasier) also did voicing for. Also, from 1998-2002 he was a Militia Man on SG-1.
Claire Rankin (Dr. Kate Heightmeyer) guess started on an episode of Charmed and Star Trek: Voyager *two of my fave shows*.
Practically all cast members have been on an episode of The Outer Limits.
Robert Davi (Koyla) did the voice of a character in Halo 2.
Ryan Robbins (Ladon Radim) and some other past characters are to appear in some show called Sanctuary. He also was Charlie Connor on Battlestar Galactica. And Amanda Tapping will be Dr Helen Magnus on Sanctuary. It's directed by Martin Wood and other actors are David Hewlett (Rodney McKay), Laura Mennell
(Atlantis: Sanir SG-1: Mary), Paul McGillion (Atlantis: Carson Beckett/SG-1: Young Ernest Littlefield), and Peter DeLuise (SG-1/Atlantis Director/Co-producer, Writer/Machine Gun Guard/Villager/Young Urgo in Uniform/Creative Consultant/Airman/Tok'ra Guard/Lieutenant/Submarine Lieutenant/Man Leaving Cafe/Loki/Supervising Producer/Kvasir/Wormhole X-Treme Replacement Actor). The shows executive producers are: N. John Smith, Amanda Tapping, and Martin Wood.
Peter DeLuise, Amanda Tapping, and Paul McGillion are in Engaged To Kill together.
Numerous cast and extras and what not have been on The Outer Limits, X-Files, Jack 2.0, Dead Like Me, Star Trek, Battlestar Galactica, Da Vinci's Inquest, ER, The Dead Zone, CSI, Law and Order, Seven Days, The 4400, Dark Angel, Jeremiah, Smallville, Eureka, First Wave, Farscape, Charmed, Andromeda, 24, Angel, Jason X, Saved, Mutant X, Highlander, Without a Trace, Psych, Blood Ties, JAG, So Weird, Bones, Supernatural, Forever Knight, or have done a voice for an anime.
Robert Picardo (Woolsey) played the hologram doctor on Star Trek: Voyager for 7 years before Atlantis. He also did a voice for Justice League just like Ben Browder.
Connor Trinneer previously played Cmdr. Charles 'Trip' Tucker III on Star Trek: Enterprise, which also starred Jolene Blalock who did a role on SG-1 as Ishta. Also, starring John Billingsley who played Simon Coombs on SG-1.
Ben Cotton (Dr. Kavanagh) was in the movie Slither which starred Nathan Fillion who was in Firefly and the movie Serenity with Jewel Staite (Dr. Keller/Ellia) and Morena Baccarin (Adria).
Ben Cotton (Dr. Kavanagh) was also in Tru Calling which had Joe Flannigan (Col. John Sheppard) in it too and Garwin Sanford (Simon Wallis) and Reece Thompson(Jinto). Who's main star Eliza Dushku who played on Buffy The Vampire Slayer which also starred Nathan Fillion who then yes the above info as well.
Garwin Sanford (Simon Wallis) played Narim years ago on SG-1 called, who had feelings for Samantha Carter.
Michael Shanks' (Dr. Daniel Jackson) wife, Lexa Doig (Doctor Lam) was on the tv show series Andromeda whos character fell in love with Michael Shanks' who guess starred with Christopher Judge (Teal'c) whom is his best friend. He was inspired to pursue an acting career while watching future "Stargate SG-1" (1997) co-star Richard Dean Anderson film an episode of "MacGyver" (1985). Appeared with Torri Higginson in "Stargate SG-1" (1997) and "Stargate: Atlantis" (2004) who co-starred with his wife Lexa Doig in TekWar (1994) (TV), _"TekWar" (1994)_ , TekWar: TekLords (1994) (TV) and Jungleground (1995). Grew up as a huge Star Wars and Star Trek fan. Michael was also a fan off the cult television series, Xena: Warrior Princess. And Claudia Black was in an episode of Xena and Hercules which Xena is a spin off of.
More then one kid such as Reece Thompson (Jinto) did a movie on The Sandlot. He also did a voice for InuYasha, Infinite Ryvius, and Rockman.exe.
David Hewlett (Rodney McKay) was in the movie Darklight which starred Shiri Appleby who was in another SciFi channel show Roswell. Kate Hewlett (Jeanie Miller) David's sister on and off the show stars alongside him, Paul McGillion (Carson), Rachel Luttrel (Teyla), and Christopher Judge(Teal'c). And after starring in A Dogs Breakfast Michael Lenic, will be Guy 1 on SG-1. The movie was directed and written by David Hewlett.
Robert Patrick (Colonel Marshall Sumner) was on the show The X-Files (Agent John Doggett) who starred years earlier in Terminator 2: Judgment Day which soon Terminator 3 would be made which starred Kristan Loken who would go to be in The L Word (lots of other extras) and the new SciFi channel series Pain Killer Jane.
Ben Browder was in a movie with Tricia Helfer who plays Cylon #6 aka Caprica on Battlestar Galactica.
And Ben Browder and Claudia Black were on Farscape together which they did a parady of in the 200th episode of Stargate SG-1. But Ben wasn't John Crichton, Daniel was and Vala was Aeryn Sun.