There aren't enough Time-Travel fics yet.
Harry Potter finds a broken Time Turner or something! (Or Delorean, if you're feeling the 80's.) HARRY ACCIDENTALLY GETS SENT BACK IN TIME!
Gasp and dismay! Oh no! Whatever will The-Brat-Who-Lived do?
Anyway, Harry totally goes back in time, to the immensely crappy year of 194-something. He tracks down the illustrious, genius, impossibly clever, and ridiculously handsome Tom Riddle …
Harry totally kills Tom. (A passionate, forbidden love affair did not happen. Or did it?)
Mr. Potter then somehow goes forward in time, using magic or some crap, because he's a wizard, and that's what wizards do. They use magic to do things. There's no point in explaining it BECAUSE IT'S MAGIC DAMMIT.
Back in the future, there was a huge Riddle's Dead party and everyone was invited, even Draco Malfoy. Fred kills Bellatrix, Neville gets the girl, someone trashes the Sorting Hat, Dumbledore magically comes back to life, everybody loves Snape, Harry gets the Medal of Honor, Ron gets a whopping nothing, and Hermione stops being a geek and finally puts on a skanky skirt (that everyone likes) and makes out with Draco. All in all, a good party.
Booze was involved. There was probably dancing.
THE GODDAMN END!