I find myself attracted to literature that creates (or re-creates) a world, or a little slice of a world.  I am not referring only to setting, but also to the characters and plotlines that inhabit these worlds.

The worlds can be imaginary, like the countries that Gulliver visits in Gulliver's Travels, or the futuristic distopia in Fahrenheit 451; or they can be real worlds whose very tedium makes them interesting, such as the little deli that stands at the center of Bernard Malamud's The Assistant, or worlds whose hypocrisy is criticized by the author, such as the French countryside of Madame Bovary.  

The book I am reading now is Penguin Island, by Anatole France, in which the author invents an entire civilization and traces its history from its ancient roots to modern times.  

Any kind of literature which holds my interest, excites me while reading, is innovative and/or unique in the manner it is told, and makes me think about it for days afterward is quality work in my estimation.

I like this thought a lot. What IS good literature? What makes it good? I think, for me, good literature is anything that stimulates an interest in a reader; if you can sit and read something and take an author's thoughts away (or a character's experience, or anything else), that literature is good.

What is GREAT literature? Well now. 

Great literature is art in its purest form -- a writer sat and expressed intangible feelings through visible words. It's music, poetry, and painting in a different format. It's effective, by use of technique and by use of imagination. It's where the wonder of an idea meets the intrigue of literary style.

I agree with others that every person gets to decide what they personally like, but to me, good literature presents me with an experience that surprises me and makes me think about myself or my world in a new way. At some point, there are only so many plots or themes in the world, but a gifted author can give me a new "slice" of an old theme and leave me changed. 

We each get to decide what we enjoy, respond to and admire in all of the arts, including literature. For me, good literature presents 1) a perspective on living as a human that is compelling and thoughtful and 2) creates this perspective through an interest in the development of a theme or set of themes. 

Literature has to be simple enough to grasp but complex enough to inspire thought. Without a perspective on what it means to be human, the book can't rise above "entertainment" (which is fine, but it's not good literature). Without the development of theme, a book also cannot rise above "mere story", no matter how poetic or fluid. 

Criteria for "good" literature differs for every reader. In the same way people tend to like specific types of music, people also like particular types of literature.

That said, my own personal criteria for good literature are:

-The text needs to be engaging

-The text needs to evoke some kind of feeling in me.

-The text needs to be free of grammatical errors and well constructed (unless you are Faulkner or a poet).

There are at least two criteria.  First, the literature should tell us something important about the human condition.  It should not simply be a fun story.  Second, the literature must be well written, with clearly drawn, memorable characters and a strong plot.