I voted other, because I hadn't made my mind up about this really, it was allways dependant on the situation. I thought about every PC I killed in an actual combat situation and how I view that situation now.
For those interested in my reasonings about these, bear with me through my small bundle of flashbacks. Those not interested: Feel free feel free to skip to my last paragraph.
Flashback 1: Sun elf killed by pendulum trap. Sounds like a very unfun way to loose youir character. It wasn't and I'd handle the situation just like this anytime again. Why? Consider the following: The charakter was under half hitpoints but declined healing. He went ahead and checked the door before the passage he was killed in, but not the hallway itself and even though the group had a dwarfen rogue that would have found the trap in no time! The passage was descriped in a way that hinted at something special, even at the trap itself (splashed blood). The trap would have been survivable at more than half hitpoints. So it boils down to either player foolishness or recklesnes on the PC's part, both carry the expectance of death in a game mastered by me.
Flashback 2: Monk is killed by a large Air Elemental in a dramatic fight with two air genasi. The strike itself was a AoO for drinking a potion while threatened. I'm split on this death. Things that speak for it are: It was a very tense and climatic fight, that I'm proud of till today. One reason was player "stupidity". While you can't give a new player the fault for not knowing the rules, this player was in the campaign and had access to the PHB long enough to know about AoO's, but didn' even bother for one look at the PHB. I don't appreciate when players make so little affort for the game. But some things sour it for me: The large Elemental from an Elemental Gem was far to powerfull for the 3rd/4th level party of 5 chars that just fought a level 5 genasi wizard and a level 4 wizard/rogue. Trusting the NPC wealth guidelines that far to not check the stats of a large elemental was a terrible miscalculation that would have TPK'd, had I not made the elemental go *poof* when realizing my mistake. And the fight was not major to any storylines. These genasi weren't major villains, but just some punks that had stolen a wand from a blue dragon. The players where out to get them only because of a sidequest from that dragon to aquire a magic orb. I should have spared such a climatic and deadly encounter for a critical point in the campaign.
Flashback 3: Makkes Uldling, Gnome artificer, killed by two flanking horrific rats in the Ebberon CS's introductory adventure. This death left a bitter taste because the player didn't take it well. I think it's still justified. Uldling was the groups hp weakest member and ran streight into a position two 5ft steps away from getting flanked, without charakter or tactical reason to do so. Big "Dooh".
Flashback 5: Elven fighter/dervish in "City of the Spider Queen". Spoiler: The charakter ran of alone back to camp, only because the player wanted to show of his boots of speed + character speed. The adventure has a Maurezi ambush planned, just for such instances. Some failed saves and a "Where is he?" later, they found the Maurezi feasting uppon his remains. Talk about foolish players.
Flashback 6: Same player, same module, gnome druid. This one really sucked and the player was at no fault. He wasn't even participating at the session, which made it suck so much. He was killed by a dominated partymember in a small fight, that was a pushover in every other respect. We looked into every way to avoid killing his character this way, but in game solutions failed because of bad rolls and out of game solutions i.e. fudging it, threatened the athmosphere and suspension of disbelief. In the end it was agreed he would get a true ressurection from the massive loot the players had, but it never came to this because we broke of the campaign, massively turned of by standart D&D high level play. Because of, among other things, 150 damage rounds, massive christmastree presence, save or die effects, unfun randomness like that one dominate etc. I think it's okey to use dominate and have dominated PCs kill other PCs. But not in small pushover encounters.
Thinking of all this, where do I fit in? Somewhere between only if it's dramatic, when the dices fall that way and out to get them. PCs shouldn't regulary die in sideway encounters and fights that are not major, unless because of foolishness, either by starting fights they shouldn't or stupid in fight behavior (if it's roleplaying appropiate, I'm a little softer on stupid taktical decisions, though such character's players should expect them to die more easily. If it's a major fight however, I'll pull no punshes. I won't make it TPK or use Save or Die effects, because it's plain unfun. But hard fights are to be expected. A dragon, Archmage or Orc Horde is a terrible foe of legend, that is the doom of many heroes and sacrifices are to be made to defeat a opponent of such proportion. In a major fight, I'm out to make things as tough as I can, while still keeping it enjoyable for everyone. If loosing a charakter in spectacular way isn't acceptable to somebody, there are enough other games in my enviorement for them. Now remember, this is my subjective oppinion, I don't expect anyone to play this way. If no one else wants to play this way, someone else can DM or I adjust, as long as my players enjoy it, I keep it that way.