Liara announces that she spent two million credits on a set of armor in a crowded elevator. Wrex's response? He pulls out a pistol and shoots her in the forehead. It deflects off of the barrier. He announces, over the panicking, the alarms, and the inquiries of what-the-hell, that she got her money's worth.
"You couldn't have tested that another way?"
During Mordin's recruitment, he makes a comment about the Eclipse leader sending in cannon fodder to soften them up. This exchange happens:
Leviathan having an Oh Crap moment when Shepard and company release the Prothean he was using to breed Collectors is both amusing and awesome to see.
On their way to kill Morinth, Shepard dresses in a Stripperific outfit and gets hit on by a hanar of all things.
When Morinth angers the Avatar, all she has to say was "This was a mistake," in an utterly calm deadpan manner as Shepard casually obliterates two buildings to use their remains as ammo.
While hunting a rogue AI, Adahn offers that he can get Shepard and Tali to their destination in sixteen seconds. One problem: doing so would involve them moving at Faster Than Light speeds, through a crowded city. And Adahn protests when Shepard asks him to take the normal route.
During the attack on the Collector ship, Grunt is attacked by several Spirit monsters. He treats the experience as if it was just run of the mill, more annoyed at the spirit he's fighting than anything.