I had the most awesome sequence just now. Standard mission, I forward my ranger, and he unlocks 2 groups of 3 aliens each, at 12 and 9 o clock, and 2 more turrets at like 7 o clock.
My colonel sniper activates Serial, which refunds all your action points if you kill something with your sniper rifle. He takes 3 shots at 3 of the exposed aliens, and kills all 3. This empties his sniper rifle, which he reloads with a free reload from an item, then I put him on Kill Zone, which is a cone in which everything that moves gets an overwatch shot.
Which kills the other 3 aliens. :-wheeee-:
6 kills in one turn by one character, not using explosives. That's gotta be a record!