Here are imo the best Spider-Man/Green Goblin stories:
1) Amazing Spider-Man #121-#122: The dreaded turning point. Norman is back and meaner than ever. This time he goes too far as the Goblin trails Peter Parker to find him dating Gwen Stacy. In a crude move he kidnaps Pete's girlfriend and takes her to the George Washington (or Brooklyn, take your pick) bridge for an ultimate showdeown. In the hey frey Goblin tosses Gwen off the top of the bridge and when spidey tries to save her, accidentally snaps her neck from the impact of the webline. Hence SPIDER-MAN KILLED GWEN STACY AT THE HANDS OF THE GREEN GOBLIN. Oh the irony. Peter goes on a rampage to find Norman even blowing off his best friend Harry when he overdoses on LSD again leading him right back to a warehouse where Norman is planning. They battle and Spidey nearly beats GG to death but pulls the last punch and will take Norman to jail instead. But GG pulls a remote to the glider to kill Spider-Man instead, but Spidey ducks and the glider impales GG instead. And to quote the book "And so the proud man dies not on a ring of gold but a piece of tin." – 1973
2) Peter Parker Spider-Man (Volume 2) #44-#38: An arguable good conclusion to the saga (though Marvel can't leave a good story dead, as we all know) as Goblin and Parker prepare for the final shodown. Goblin visits his son at the graveyard who he calls weak and refuses to visit ever again. He laments that he is a father without a son and Peter is a son without a father. He makes one last offer for Spidey to join and continue the Osborn legacy, when Peter refuses, he captures Flash Thompson, who is trying to recover and fills him with enough whiskey that he is like 8 times over the legal limit. He then puts him in a semi and drives it into Peter's school (killing Peter's hamster for the record). Flash is in a coma and peralyzed as Norman escapes despite Peter's spite in public of Osborn. He mocks Flash along with Harry to Peter's face. They have a final showdown at a chemical plant where after televising to the world that it was Spider-Man's fault that Gwen Stacy died and GG tried to save her, mocking Gwen's boyfriend should hate Spider-Man, the **** hits the fan. When Spidey has the upperhand GG mocks he will have another wife and child, a true heir and he'll just kill the weak little Normie (too much like Harry) to keep the bad genes out. Spidey beats Goblin to the point of killing him. But stops. The two sit there, enjoy a conversation. Lament the past and GG reveals he almost called himself Mr. Coffee which they share a laugh over. Peter misses Gwen and decides that he loves her taht in her memory he won't be a monster like Norman and will not kill Norman. He won't even put Norman in jail, because being Norman is life without parole. He challenges Norman to kill his aunt or wife, he won't stop him because in the end he is resilent and Norman is alone. Spidey wins. Norman goes to his office, pulls a gun out of his desk and puts it in his mouth. Seemingly committing suicide over this sad truth. – 2002
3) Spectacular Spider-Man #200: The Goblin has another last stand. Here Harry is maricoulously (or lazily written) released where he tries to turn over a new leaf. He scares MJ as Gobby but won't hurt her, meanwhile scaring his wife into accepting him as "normal." He then makes plans to kill all of his father's old friends calling them "snobs" who tried to keep his father down. He does it in the guise of a charity building but not before Spidey has anything to say about it. But as Peter enters this world he enters it when MJ and little Normie are in the building (little Normie is getting ****ed up and enjoying destroying Spider-Man dolls). In this time GG actually defeats Spider-Man. But he can't kill him because he breaks his promise to MJ if he lets her die, much less his son. In a moment of identity crisis, he chooses to be a hero and saves them. He comes back for Peter at MJ's urging puts his ailments (from an overdose on Goblin Formula) to its limits and dies from an O.D. Spider-Man rides with him in the ambulance to the hospital. He is D.O.A. once he is there though. -- 1993
4) Amazing Spider-Man #96-#98: Thre dreaded and feared: drug issue(s). In it Norman breaks down from chemicals and remembers his alter-ego and has an identity crisis and gives in to the Goblin. Meanwhile his son Harry Osborn is tripping off LSD and pills he bought and goes trippy. He overdoses just as Green Goblin attacks his and Peter Parker's apartment in an attempt to kill both of them! AT which point he reveals himself to be truly far gone by almost blowing up his own son but in the end losing the battle to amnesia yet again. – 1970
5) Trick of Light (Amazing and Peter Parker Spider-Man #25, Volume 2): In this we get a great little psychological story. Norman goes back to the house that his father drove him mad with. Locked alone in the dark as a boy during a stormy night by his father he learns to love the dark and it warped his mind ever since. He intends to make an heir witih this house. Peter Parker has been drugged by Norman into pretending he is the Green Goblin (I guess Peter is Goblin V? Think that's right) and he kills or tries to kill his own friends anyway at the time. Spidey then comes nad saves him. Peter figures it out and is drugged up the wazhooe and has hallucinations of his parents, Uncle Ben and you name it. Norman takes Peter to this house and will make Spidey an heir to the Goblin and Osborn legacy. Peter thinks Norman is nuts but after weeks of torture where if he chooses light he is electricuted Peter continues to fight, even as the drugs make Norman into Uncle Ben. While at first resilent by the end of three weeks Peter is a bearded, broken cowering man scared of light. Norman gets Peter about 5 inches away from drinking the Goblin formula and turning into a Goblin himself permanently when he remembers what his aunt said and throws it in Norman's face. They have their most graphically drawn grapple on the buildings roof in a rainstorm with blood flying. Norman decides to leave this for another day where their next fight will end with one killing the other. -- 2000
6) Peter Parker Spider-Man #75: The end of revelations. It is Halloween night and Spider-Man is out (Ben REilly) as Peter rushes to the hospital to see his baby. There is a sense of carelessness from the hospital staff who can't help him find his wife and daughter. He is then drugged and kidnapped and wakes up in the original Spider-Man duds in the hands of....NORMAN OSBORN. Back from the dead as it were. He reveals that the Goblin Formula gives you an advanced healing factor and his body mended itself hours after Spider-Man left him for dead. He was then to seek revenge but found his son trying on the Goblin gear so instead put a "lookalike" in the coffin and went to attend shady tidings in Europe over the last years leaving Harry to make him proud. But no....Peter Parker killed his son and Norman came back wanting revenge. He is now one personality, evil son of a *****. He has gathered all of Peter's friends over the years (Betty, Flash, Liz, JJJ, Robbie, Gloria, the whole gang) inside the Daily Bugle for a "Halloween Party" but locked them there to blow up. He reveals he has tortured Peter from Europe. Having blackmailed Ben's friend into saying Peter was the clone. But Peter was too damn resilent. Norman had already beaten Ben to a pulp. The Goblin then taunts JJJ and reveals his (JJJ knowing Norman Osborn's voice) return before Spidey keeps him from dropping him to his grave. In a very personal battle on top of the Daily Bugle explosions abound. Ben saves everyone inside and brings the booby trapped bombs in the news room to Peter who is struggling with Norman. When all seems won the remote control glider goes after Peter but Ben jumps in the way as it sends him off a building, killing Ben Reilly. Spidey turns in a huge rage against Norman. Spidey tries to blow GG up and kill him for good but he taunts he will be back and he has already won, taking from Peter what Peter took from him. When he gets to the hospital he discovers GG stole his baby May and in all liklihood killed her. – 1996
7) Spectacular Spider-Man #189: The return of Harry in possibly his most poignant story. Here he kidnaps his wife, son little Normie and brother-in-law Mark (the former MOlten Man) into his old Osborn Estate (a home that scared him too much as a sane Harry Osborn to live in) and there tortures his family. He literally beats Mark for being band abuses his wife mentally as she goes on the verge of a mental breakdown of seeing her husband reduced to a madman who is pretending to be his father dressed in a Halloween costume. Always around him pictures of he and his father painted and mounted. He even sets the seeds of maddness in his son as he forces his to side against his mother. And then of course you got him living an exploding Spider-Man in MJ's bed and Peter trying to stop it and being the guest of honor at the cooky dinner party that ends Harry as the GG finally being caught and carted off in chains taunting he knows who Spider-Man is and soon he will reveal it to the entire world. -- 1992