What makes a good story?

I know I've heard people ask this (to better authors than myself, as I don't generally think my stuff is any good), so I'll try to cover a few points:

1) Originality*
2) A plot that fits the genre (or non-genre, for literary fiction)
3) A conflict

Yeah. That's all it takes. I'll cover these points one by one.

1) I marked this with an asterisk because there's no such thing as a new idea. The key to having an original story is to use a tried and tested idea and tweak it so it APPEARS original. I don't mean read a book and reword every sentence. I mean pick a general topic and change it. For example, let's say you wanted to write a story about vampires. What makes your vampires different then all the classic vampires (Nosferatu, Dracula, Lestat...not necessarily in that order) and the..."Pop"/"Fad" vampires (Edward Cullen)? Here's an idea! Make them created through scientific means (i.e., a medicinal cocktail). Now it's time for research. I know, the dreaded 'R' word! But to make a story believable, you NEED research. I spent an hour researching Walther PPKs for a part that didn't even stay in Iron Cross. I also spent weeks researching combinations of medicines that could create a vampire (bloodlust, anti-resistance to sunlight, pale skin, super-strength, and super-speed) without causing INSTANT DEATH. My way would make the injection EXCRUCIATINGLY PAINFUL, even worse than a Rebif injection (Multiple Sclerosis meds that kill your immune system so it doesn't eat your nerves and brain...you're injecting acid just below your skin...yeah). Anyway, back on topic. You need to come up with an idea and research a way to do it that hasn't been done before, but is believable.

2) Okay, this part is TECHNICALLY not that important. Lots of craptastic novels make New York Times' Best-Seller List. Look at Twilight (I know I'll be brutally murdered for insulting this "great work of fiction"), for example. Basically, all you need to do is look at the genre's formula (Romance novels, the current most written novels at about 90% of fiction if I remember correctly, follow a formula that's fairly easy to pick up: Two people fall in love and have sex. Or at least that's what I gather, never having read a TRUE romance novel. I prefer macabre fiction). I can't tell you all the formulas for every genre. The best way to figure it out is to read a book or two. The more the better.

3) There MUST be a conflict. Without a conflict, your story has no plot. No one reads a story with no plot (even Catch-22 had a plot and it's known for not having one). Conflicts can come in many varieties. There are two MAIN kinds, however: Protagonist vs. AntagonisT and Protagonist vs. AntagonisM. The first is what is generally used in JRPGs: Good Guy(s) vs. Bad guy(s)/Evil Empire. This CAN still work in novels, though...it's a little on the "This should be a game, not a story!" side. Books of this type include: Ring (Reporter vs. Virus), Spiral (Doctor vs. Virus), Loop (Kid vs. Virus), Moby Dick (Man vs. Whale), and the Lord of the Rings Trilogy (Frodo vs. All those evil dudes and that f'ing ring...though the book is mainly about walking). Protagonist vs. Antagonism, on the other hand, is what is much easier to write and generally has a deeper meaning.
"WHAT?! Easier to write AND has a deeper meaning?!"
Yes, you read that correctly. Pick a topic. Research it. Write it. See? Tip 1 is still paying off here. Now, that seems a little simplistic, doesn't it? I'll give some examples of books you can read that will explain it better than I can. Famous works that are Protagonist vs. Antagonism: George Orwell's 1984 (Man vs. Society), Anthony Burgess' A Clockwork Orange (Man vs. his own past), Vladimir Nabokov's Lolita (My favorite book, Man vs. his own mind, though he's losing the fight...the book was written as evidence for a court case (fictionally)), and Fyodor Dostoevsky's Notes from Underground (Man vs. Loneliness, though the book is mostly just a long rant, but it's f'ing hilarious if you understand Russian humor...if not it's depressing as hell). I only recommend these because they're often more memorable. I'd also recommend all of Stephen King's books as Richard Bachman. They often make you question what's right and wrong (Specifically The Running Man, which is the name of a game show in the book, where a man goes into the Games Corp. to register to be on the show because his family needs money...badly. The game show he gets on is The Running Man, where he has to run from a man who is trained in hunting people. It's powerful, but it's...Society vs. Itself).

And on a sidenote: AVOID fan-fiction. That's just plagiarism lawsuits waiting to happen...and those stories automatically suck because you are not the original author and everyone has his or her own voice. You're ruining what could have been a perfectly good story...or a fad book. Either way, people rip that stuff off all the time. If you're going to take the time to write, take the time to come up with your own ideas.