The ability to scare the enemy into submission with a weapon in the Metal Gear Solid series, especially right before you knock their lights out. I feel more games should have something along the lines of that mechanic.
the Melee ability of the M.E.C Troopers in XCOM: Enemy Within. Nothing like punching Mutons and Mechtoids into a car and watching it explode on impact as they die.
Elizabeth's Tear opening ability in Bioshock Infinite, All those medkits and friendly machine gun toting automatons really helped a lot to say the least
The Half-track's ability to reinforce squads in Company of Heroes, Better than having to train a new squad entirely and have it run across the battlefield in the heat of combat when you really need to shore up a line really quickly.
and finally, although nothing of real tactical value, I did love the character customization options in XCOM: Enemy Within, which allowed me to put a distinct look on each member of my teams.
the Melee ability of the M.E.C Troopers in XCOM: Enemy Within. Nothing like punching Mutons and Mechtoids into a car and watching it explode on impact as they die.
Elizabeth's Tear opening ability in Bioshock Infinite, All those medkits and friendly machine gun toting automatons really helped a lot to say the least
The Half-track's ability to reinforce squads in Company of Heroes, Better than having to train a new squad entirely and have it run across the battlefield in the heat of combat when you really need to shore up a line really quickly.
and finally, although nothing of real tactical value, I did love the character customization options in XCOM: Enemy Within, which allowed me to put a distinct look on each member of my teams.