It's been so long since I last died during normal gameplay I couldn't tell you. Last time in a modded game was from a Dark Wolf in my Survival mode that wasn't mod. Last time normally... I'm going to blame lava.
I ran from a creeper. Off a cliff. Into an enderman. I froze there, not looking away so it wouldn't attack. I forgot about the creeper, which dropped off, and blew up behind me. And then the enderman killed me.