Enrico Colantoni
Enrico played Burke the CIA operative Burke who alas only appeared on SG1 once in the episode Evolution Part 2. He is better known for Just Shoot Me, Flashpoint,Veronica Mars and more recently Person of Interest, Powers, American Gothic and Carmilla. IMDB Twitter
Kristen Dalton
Kristen played the doomed Anna in the SG1 episode Resurrection and Dana Bright in The Dead Zone. She has also appeared on Sliders, Profit, Last Day on Earth, CSI:NY and Jack Reacher. IMDB Twitter
Frank Collison
Frank was Keturah in the Atlantis episode Sateda and has also guest starred on Carnivale, My Name is Earl, Dr Quinn Medicine Woman, Mr Pickles, American Horror Story and Deep Space Nine. IMDB Twitter
Graham Kosakoski
Graham played a guard on the ancient starship Aurora in the Atlantis episode of the same name. He has also been in in Intelligence, Grizzly Rage and Smallville. IMDB