If you have Legion as a squad mate on a mission or go visit him in the VI core and wait a couple of minutes he will proceed to do the dance: The Robot.
If one flies to the Local Cluster and investigates Uranus, EDI will say a few humorous lines at one's attempts to launch probes into the planet.
While doing lines that involved the Illusive Man smoking, Martin Sheen would suck on a pen because he doesn't smoke.
When Miranda's character was originally created, she was a blonde of Scandinavian heritage, named Miranda Solheim. When Australian actress Yvonne Strahovski signed on for the role, Miranda's last name was changed to the more Australian name Lawson, and her hair color was changed to black, which matched better with her white and black uniform.
As Shepard chases Vasir during the "Lair of the Shadow Broker" mission, a wanted poster for Jack is displayed above a tunnel.