Here's Genobee (video courtesy of xmszeon):
Notice how he never bothers to dodge the player's attack except for hopping occasionally to launch grenades (or alternatively, hovering the whole time while firing grenades). Just pour lead into him until he dies really.
Agraya (as played by Terminator98, skip to 1:19 for the actual battle):
And then there's Mollycoddle (courtesy of ArcadiaH69S, skip to 2:53):
His erratic movements make him slightly harder to target, and he actually uses his rifle.
Edit: Fixed some errors.
Agraya (as played by Terminator98, skip to 1:19 for the actual battle):
And then there's Mollycoddle (courtesy of ArcadiaH69S, skip to 2:53):
Edit: Fixed some errors.