I liked Spark. He was funny, I didn't want to kill him
. Well I used pretty much every last single bit of ammo on him before I saw the laser on the ground. That did the job real quickly.
I used to just circle a heavy armor vehicle with a wharthog and keep on doing so untill the guy in the back did enough damage for it to go boom. Somehow I don't think I'll get away with that in Legendary mode though :P.