The one with the power to vanquish the Dark Lord approaches ... born to those who have thrice defied him, born as the seventh month dies ... and the Dark Lord will mark him as his equal, but he will have power the Dark Lord knows not ... and either must die at the hand of the other for neither can live while the other survives ... the one with the power to vanquish the Dark Lord will be born as the seventh month dies ..."

Harry Potter and the Order if the Phoenix J.K. Rowling

As we all are very familiar with, Lord Voldemort decided that the half-blood contestant for the prophecy was more of a danger than his pure-blood counterpart, Neville Longbottom. My fellow author and I, Creager, have twisted our brains to produce the alternative results of Voldemort's different choice.

Voldemort enters the Longbottom residence on Halloween night. His parents, as stated in Rowling's series, would sacrifice themselves as the Potters had done. Now our dear friend Neville is Scarface, without the drugs and women.

Neville goes to live with his next in line, his strict grandmother. That is, unless she happened to have been the secret-keeper for the Longbottoms, in which case she would have been tortured for information. Thus is the curse of the Longbottoms. If she had been chosen as the poser secret-keeper as Sirius was in Rowling's story, then she would be imprisoned at Askaban. For storytelling purposes, we're going to go with the third option that she was visiting her grandchild, and was slaughtered by Voldemort as well.

So now we need a nice wizarding home! :D We have the only remaining family member mentioned in Rowling's series, which is Neville's uncle. This figure apparently threw Neville out a window to test if Neville was a squib. When Neville bounced, the family discovered he was indeed magical. If in our story Neville lived with this uncle, he would no doubt be pushed to extreme limits and pass away. Thus we arrive at Neville's first death. DEAD.Neville's death would lead to Voldemort's return during Harry's second year at Hogwarts.

Or, another wizarding family can be selected. Most likely Dumbledore would pull from the Order, choosing a family with a boy Neville's own age. Enter the Potters! :D (Still Alive!) Neville would be treated to a lovely childhood growing up with Harry, and the pair of them would be taken to Platform 9 ¾ by Lily and James. It is also worth noting that Neville would receive Olivander's wand with the matching phoenix-core wand instead of Harry. If he was not chosen by this wand, then Neville would perish in Goblet of Fire. DEAD.

If by some chance Ron does not sit with Harry and Neville, fate would be totally screwed up and would cause in their eventual deaths when faced with the chess board in the Sorcerer's Stone. DEAD. Ron's awe of the Boy Who Lived would likely cause them to sit together, however. Especially when Harry brags that Neville is his "brother". Creager and I assume that Neville's toad would make a dash for it. This may or may not result in Hermione meeting the trio. This does not influence the plot too much, as she meets them during the Sorting ceremony.

And here is our Sorting Hat dilemma. Neville possesses a shard of Voldemort's soul, giving him a free pass to Slytherin. This would have the unfortunate result of Neville not being friends with Ron and Hermione, along with the absence of Harry. This means that when traveling to get the Sorcerer's Stone, Neville would fail the tests and perish. DEAD. Voldemort would not figure out Dumbledore's genius mirror, but would make a come-back during Harry's second year. Let us assume that Neville is strong-willed enough to get into Gryffindor. This means that the curious Harry, Ron, and Hermione accompany Neville to get the stone. Harry would be trapped with Hermione in Snape's puzzle room, allowing only Nevile to continue. That means that Neville is able to give Quirrell a big hug and save the day.