Yizzik

When up against melee-only aliens (chryssalids and reapers), follow them around with a flying suit, raining grenades on them. The other main use I make of flying suits is to get them straight up in the sky with blaster launchers (usually two of these for ship-cracking operations) and provide an long-distance aerial assault that effectively covers an infantry charge. This is particularly useful against downed/landed battleships, as you can completely destroy the top two levels of the ship from the air, while the troops clear out the bottom levels. This way yields more elerium and ship parts than trying to fry the entire ship with blasters (can anyone honestly say they haven't done that?) and is a damn sight easier than clearing out the whole ship with ground forces.

One soldier, one chryssalid. Facing each other down. It's the moment of truth, with not a single blast left in the plasma rifle. Not having the time to prime and throw a grenade, the soldier has to make a choice. Blow himself up to save the rest of the squad from chryssalid swarms, or the much sillier option. Forget priming the grenade, just throw it anyway. I had no idea this could happen, but the unprimed grenade smacks the chryssalid on the head and knocks it out cold. Sir, we've got a live one!