I've been doing this for a while, and I've killed a great many PCs over the years. My homebrew games are tough, really tough, but rewarding. I've no compunction about having the enemies go all-out against the PCs because they too are fighting for their lives.

I don't recall my first kill. But a pretty decent recent one was in CotCT, I scored a max damage critical hit with a spear through the fighter's chest. That was the first death in that campaign and it kinda shocked the players into not rushing in.

I do give my players a freebie though. Everyone gets one character death. As in, one DM-fiat-resurrection without penalties. Precisely because I start my games at 1st level, and I'm not stingy about having them fight stuff that's quite able to drop them rapidly if they're not smart about it.

For my upcoming game, my girlfriend has rolled up an archery ranger...she rolled high for starting gold and purchased herself a decent composite bow with strength bonus, and didn't buy any armor at all (!) so her AC isn't high as it should be. She'll be relying heavily on the others to keep her alive until she finds some armor or can afford some. Should be fun.

Another rather amusing tale...while not quite character death, they came within inches of their lives. In the same campaign, the party was fighting some rather interesting creatures. Plant-type demi-genies who could fly, had reach, and liked their Large scimitars very much. The party was having issues, as there weren't many ways for them to get up within reach of hitting the things, and the fighter was having serious issues with his crossbow. The rogue/swashbuckler/oracle/whatever managed to get high enough to grab onto one of them, and dealt some decent damage...but while he was hacking away, the thing floated off the edge of the cliff. And tossed him off. He made a spectacular effort to reach the cliff, but missed, and fell....took a decent amount of falling damage, into water, but the real trouble for him came when the monster in the water went "mmmm lunch", the creature itself a couple CR above the party's average level...and he was alone and heavily wounded and encumbered. He BARELY managed to escape with 2 hit points, meanwhile the fighter had been knocked out, the gnome had gone invisible and hidden, the bard was running away. They actually managed to come back from that and beat the things, amazingly, with the cleric managing to find them in time and healing them all. It was a damn good battle. There's nothing cooler than a gnome riding an unconscious fighter across a Greased floor flinging magic missiles.