Subverted: It turns out that Bob was just a bit dazed. He's still there.
Double Subverted: "New Bob" was just pretending to be "Old Bob". Old Bob's still "dead".
Parodied: Bob shows some Character Development and Alice acts as if he's become a completely different person.
Zig Zagged: Bob shows signs of regaining his old personality, but only in periodic spurts. For the most part, he's "dead".
Averted: Nobody is killed, physically or metaphorically.
Enforced: The Moral Guardians won't allow Bob to actually be killed. The writers use this trope as the next best (well, tragic) thing.
Lampshaded: "What do you mean Bob's dead? He's standing right there."
Invoked: Alice destroys Bob's mind as a way of getting rid of him without being technically guilty of murder (obviously the legal system doesn't work that way, but nobody told Alice that).
Alice uses the still living but personality-less body of Bob as a slave.
Alice "kills" Bob so that she can use his empty body to create a copy of Charlie.
Defied: When Bob takes a serious blow to the head, Alice gives him a Mercy Kill to avoid this trope.
Discussed: "What if I fall over and bang my head!? Even if I don't die my brain'll all be messed up and the Bob you know and love would be gone!" "We'd try and deal with the grief."
Conversed: "So the brain tumour destroyed his personality without killing him?" "Well technically he is dead; I heard they wanted a new character but couldn't afford to hire a new actor or get rid of the guy playing Bob."
Implied: Bob is a minor character who our heroes find with a severe head injury. It cuts to them explaining to Alice that he might never be the same again without elaborating (or showing what Bob was like before or after the injury).
Deconstructed: Whether or not Bob still counts as Bob or a new person is explored thoroughly, including the legal and ethical consequences of his unique status.
Reconstructed: Ultimately, Bob and everyone around him, come to terms with what happened and he's accepted as who he is.
Played For Laughs: "New Bob" tries to reclaim "Old Bob"'s life, with hilarious consequences.
Played For Drama: Everyone struggles to cope with the change in Bob's personality and accept that he's truly dead. In some ways, having "New Bob" around as a reminder makes things even worse!