"Tomb of Horrors, for character level 1-30. Because the Sphere of Annihilation doesn't give a fuck what level you are."
Actually, the sphere is no longer a insta kill. It'd probably kill a low level PC, but any trap at that level would probably kill a low level PC.
Sphere of Annihilation
no longer an insta kill
Someone somewhere is doing it wrong. It's a sphere of annihilation. A magical disintegrating black hole of doom. It shouldn't even be Save or Die, it should be Touch it and Die. Not that I am in favor of rampant player killing, but if the Sphere of Annihilation can't kill you outright what can?
....
I think ending all the Save or Die effects is just a setup for a sourcebook. Later this year they'll release the Tome of Mortality, with a whole bunch of new spells, creatures, and items that have save-or-die powers. There will even be new paths for the core classes, such as the "Master of Disintegration" wizard path, or the "Headchopper" fighter path.
Shortly following that will be the Book of RogueFuckery, which makes everything immune to sneak attacks, poison, and criticals.