The Many Afterlives of Jason Todd:

Jason's memorial
AS A MEMORIAL
In the Batcave, Jason Todd's case hangs behind glass with a plaque reading "A Good Soldier".

Jason in heaven
IN HEAVEN
In Green Arrow : Quiver #7, Jason is among the familiar faces in heroes' heaven.

Jason in purgatory
IN PURGATORY
In the Day of Judgement mini-series, Jason is among the vigilantes in purgatory.

Jason being taken to hell
AS A CAPTIVE IN HELL
In the mini-series Deadman: Dead Again, the souls of fallen heroes are being stolen and kept captive in hell as part of a ritual to give power to a dark magician. Jason spends much of the story trapped in a cage surrounded by fire and demons. When Deadman triumphs over the villains, the captured heroes are set free.

Jason with his eyes put out in hell
IN HELL
In Batman & Demon, Batman has to venture into hell. There he meets Jason, whose eyes have been put out by red-hot spikes. After reducing Batman to tears and horror, 'Jason' transforms into a demon and flies away, laughing.

Jason as a ghost
AS A GHOST
In Gotham Knights #34, the black-and-white short The Delusions of Alfred Pennyworth suggests that Jason might possibly continue to inhabit Wayne Manor, and that the second Robin is still watching Batman's back.

Jason appearing in Dick's 'hallucination dream near-death experience whatever'
AS AN 'HALLUCINATION. DREAM. NEAR-DEATH EXPERIENCE. WHATEVER.'
In Nightwing, during moments of severe emotional stress or doubt, Dick has sometimes been 'visited' by Jason. Jason dispenses his own special brand of sage advice, essentially giving Dick a kick in the metaphysical ass when he needs it. ('Hallucination..' description taken from Dick's dialogue in SF&O;)

Jason as Bruce's temptation
AS A TEMPTATION
During the Underworld Unleashed cross-title storyline, heroes and villains alike are offered their heart's desire in exchange for their soul. For Bruce, this takes the form of a chance to have Jason back. Stronger in the face of such an offer than many of the other tempted, Bruce declines.

Jason's corpse, complete with sign
AS A POLITICAL ADVISOR, OF SORTS
In Emperor Joker, when the Joker became all-powerful, he assembled the corpses of the three Robins (having had Tim and Dick killed) to act as his think tank. He pretended to hear advice from Jason, commending that he could see now how Jason had earned the title of "the naughty Robin".

Jason's skeleton, put on display by the Joker
AS A TROPHY
In Batman Chronicles #16, a collection of strange artefacts is found in an abandoned building, including a skeleton dressed in a makeshift Robin suit. It is on display in a glass case, along with a crowbar and a placard reading 'The Day I Won'.