I'm fairly certain that your post is the first time I've ever seen the phrase "too much character development."

I like stories that tie in closely with the Lore and perhaps expand on it a bit.

I don't like long stories. I should be able to read the whole thing in less than 10 minutes.

The story should have a conflict and climactic resolution.

The author should understand his/her audience and the stories should be written for that audience.

I appreciate good grammar and spelling, which requires carefully proofreading the story several times.

My Dragon Princess Chronicles are just quick, fun stories that try to do the above.

Characters

*I'm a big fan of character development, and characters that you can tell the author thought a lot about their background and motivations, even the ones that don't come to play in that particular story. Flaws are important, and the most flawed characters are often the most interesting to me. Give me a weak character, a frightened character, one that's doing their best to overcome what's being thrown at them. Maybe they're not sure they can do it, or they're positive they're going to fail, and maybe the reader has their doubts as well. Give me a character who makes mistakes, who makes things worse before they manage to make things better. Unwavering competence is boring.

*I don't like "badass" or "I work alone" types of characters. If a story includes these and they don't immediately have some character trait that makes them interesting, I stop reading. Characters who are better at almost everything, more good-looking, or whatever else, than those around them are bland wish fulfillment. Badass protagonists tend to be popular in the Vault, thus why I've never read more than a few paragraphs into most of the stories here.

*I like to see relationships. They don't have to be romantic - I want siblings and parents and best friends and annoying next door neighbors and favorite teachers and that supervisor that just won't give the protagonist a break. Characters need a network of people they know, and sometimes of people they wish they didn't. So many characters seem to exist in the vacuum of their own stories, as if they popped into existence shortly before the first sentence. Every person who the character has never known doesn't need to show up, but I want to see that there are other people with personalities and backgrounds of their own hanging about, not just a bunch of faceless extras.

Plot and Settings

*I'm not all that interested in the heroes saving the world. How many times does it really need to be saved?

*I don't like it when every element of the game is used - I don't want to see a description of the character's Military Flak Jacket and every accessory they're wearing. Some game mechanics make no sense outside a game, and I dislike seeing them used as part of narration. If an author wants to use specific parts of the setting to make it authentic, great, but I want to see them hedge those elements in originality. Lore is great, until it burdens the narration with describing all of it. Not every scrap of background information created for the setting needs to be outlined in detail for me to enjoy the story ... in fact, as much as I like lore, reading paragraph upon paragraph of exposition with no plot bores me. Then again, I'm not a fan of crack lore, either.

*I like to be able to recognize the setting as the setting, and new creatures that are introduced need to make sense to me. Dropping pegasi or tanuki onto Cradle with no explanation of why they're there is going to make me roll my eyes and click off somewhere else.

*I'll read long fanfics if they really grab me and the characters are stellar, but shorter is usually better.

*I can take or leave combat. Same with romance. Melodrama can be dropkicked into the core, though. I enjoy drama, action, humor, or a mix of all three, as long as the humor isn't some uncreative slapstick or toilet humor thrown in to be random. I prefer dry wit or a bit of poking fun at the absurdities of everyday life.

*I don't need a huge climax with a big action scene, or even a sweeping plot. I enjoy slice-of-life stories where people just do stuff. The antagonist doesn't have to be some big, bad, evil ... it can be an obstacle (self-imposed or not) or just the character's own foibles.

.... I think I've rambled long enough.

There is so much that makes a good story a good story.

First of all, the idea of the story has to be fresh. No matter how well-written it is, a generic story about Spiral Knights crashing on Cradle is boring to read. We all appreciate the effort put into those stories though.

Second, the story has to make people think. Whether it's through being interesting, funny, or by withholding information from readers, it makes stories much more memorable. Here is a poem that is so short but so inspiring.
-------------------------------------
Me

We
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That is what I call freaking art.

Third, the stories need to make a connection with real life. Stories are easier to understand and much more entertaining to read when people can make connections to the story.

About grammar and stuff, spelling is absolutely necessary. I am okay with grammar mistakes, as long as it doesn't ruin the effects of the story, or break the "flow."

That is what I believe makes a great Spiral Knights story.

I would really like, for prose, to be really loose on genre and content. I'm finding it harder and harder for people to write their own fanficts when you have bigots like Malkalack criticizing people's every move, and now that the criticism is so harsh these days, it's hard to find an author who's just willing to put themselves out there and create a good story without any worries. All I want to see are good ideas and good character interactions, with in-depth description and dialogue.

And for roleplays, I would like to see future roleplays be about the topic that the GMs has set. I know many of the roleplayers here have really good stories, but sometimes, sharing air time is needed to sustain other players, and in turn, the whole roleplay. So if we can have our roleplayers here create plots that fit into the story appropriately, instead of derailing to ridiculous shenanigans, I'd be a happier Knight. I'd also like to see posts that are almost threaded to one another, so that they don't "go on ahead" without the other roleplayers' given consent (and EVERY SINGLE ONE, not just one or two), so that players can advance together, not just an elite meta-game group dictating other's actions by throwing their weight around.

Did I mention about http://en.wikipedia.org/wiki/Munchkin_(role-playing_games) ?

Or http://en.wikipedia.org/wiki/Min-maxing ?

Or even http://en.wikipedia.org/wiki/Optimization_(role-playing_games) ?