My most memorable death was due to it being so funny. Original Half Life deathmatch. Level: Jail Cell Rats (or possibly one of the other similar variants).
I was low on armor and ammo, so I run into the one hallway that's next to the big grate on the side of the map that you get the rocket launcher in. I wanted to see if any had recently spawned in the hallway. At the other end of the hallway, for those unfamiliar with the map, is a little cubby-hole on the right side with a ladder going up to the next level. This is kind of the bottom corner of the whole map. I'm running in the open end of the hallway just as someone jumps down where the ladder is. Both of us were looking for the ammo and armor, and it hadn't re-spawned yet from whoever last got it. So, I had my pistol out and so did this guy. I'm firing; he's firing; we're both strafing and hitting nothing. We both run out of bullets pretty much simultaneously, so we both pull out crowbars and go to wail on each other. He's a little quicker on the draw, so he gets the first hit in, as we're dancing around in the tight hallway, hitting each other and trying not to get hit ourselves. I think because he got the first hit in, he won, because we were about evenly matched, blow for blow. So he finally kills me, and through our dancing, he's ended up in the cubby-hole next to the ladder. My kill-cam has me looking up at him. He looks down at me for a split-second, as if to make sure I was actually dead. At that exact instant, a grenade lands right on his head from above. I don't know if someone deliberately threw it on him or if it simply missed and fell from a throw that missed someone else. Plus, it's pretty unlikely for the grenade to actually land on your head, rather than bouncing off it and landing on the ground. But anyway, the grenade *plinks* on his head. Hearing the sound, he looks upward, right at the grenade, and I swear that if I had seen the guy behind the computer, he would have been like "What?" right before he exploded. It's like for a moment, he forgot it was a multiplayer game, and that I wasn't his only opponent. All I know is I burst out laughing at the whole thing.
It was so fast, too. Within a few seconds, it was *Run!* *see each other* Oh crap! *Bang! Bang! Bang!* *click* *whip* *WHACK! WHACK! WHACK! WHACK!* *DEAD* Whew! *plink* What? *BOOM!*