Okay well it's about time I made an entry. Let's start with the first Mass Effect...
Wrex: ~Well there was that one time when the turians sterilized our race. That was fun.
Shepard: ~They kind of did the same thing to us! (referring to First Contact War where a few hundred colonists were killed)
[I don't know which is worse, that Shepard lives under a rock and doesn't understand the genophage, or he does and actually thinks it's in any way comparable to the FCW.]
Shepard: ~Asari can mate with their own species??
[I was actually not aware of this one at all, but apparently it exists].
Salarian Councilor: ~The Reapers are obviously just a myth.
Shepard: 50,000 YEARS AGO THE REAPERS WIPED OUT ALL LIFE IN THE GALAXY, AND IF THEY RETURN IT WILL HAPPEN AGAIN!
[What a great defense. Inform them of the ramifications of a threat they don't believe exists.
Furthermore, how is Shepard so certain about the Reapers' history? Before Virimire, he does not even realize that Saren's ship is a Reaper itself, but is so certain that the Reapers are an existential threat over a hunch?]
Liara: "Male" and "female" have no real meaning to us. We do have maternal instincts, though. So perhaps we would fit what you consider a female role."
[... so, like I said, you're a female. And you're wrong].