I like a lot of 3.0 stuff. So much so that I allow or incorporate much of it into my 3.5 campaigns. And a lot of it has been either re-done or replaced by better things in 3.5.

For example the necromancer from "secret college of necromancy" was never re-printed but in 3.5 they had the Dread necromancer. The "true Necromancer", "Pale master" and other such 3.0 originals were more or less ported with some minor changes that often resulted in a more powerful class. But the Death Knight was almost totally abandoned except for in the Monster Manuel. It gave us an undead monster called a "death knight" which in some way is a shout out to the 3.0 original that has the class feature "Death Knight" at level 20 which gave it the undead subtype. But still its a far cry from a playable class.

I would love to have a 3.5 homebrew that was well balanced to do the death knight justice (or injustice or whatever)