My favorite kills are stealth. Sneaking up on a group of raiders, and shooting the grenade on one's hip. They all essplode.
I do it pretty often, too.
My most life saving kill was just getting out of Raven Rock, I had Gauss Rifle. I had no HP left. Maybe 10 health total. A DeathClaw comes after me, lunges at me, and I no scoped him in the chest, it did critical damage, and he went flying back and landed spine first on a rock and died. The best part was when he smashed his head on the rock. I know the shot killed him, but it looked like hitting the rock killed him, because of the way his spine smashed and his head whiplashed into it. Favorite kill of all time. Then some hunters attacked me. Not sure why... They didn't even have strange meat in ther inventory.. But I had already healed, and Fawkes was on my side.