In one night, I read all 9 Suzumiya Haruhi light novels. (Okay, not really all of it. I skimmed a bit.) I also read a bit of the manga.
(Just so you know, Hare Hare Yukai is as far as I ever intend to get with the anime.)
I also read a couple online descriptions. However, there was something that I disagreed with. Most sources had something along the lines of this:
"Although the story is told through Kyon's point of view, Haruhi is the main character."
...I don't think so.
Most of the plotline occurs behind Haruhi's back. What with Yuki modifying the baseball bat/Yuki reprogramming the computer game/Mikuru (big) showing up/Yuki altering reality/Itsuki doing...whatever he does/Yuki messing with that strange boy's head/Itsuki being his esper-ish self/Yuki fighting with Asakura (ohgog, Yuki is in a lot of these) are important elements in the plot. Not to say Haruhi isn't important - she's the whole point of the story - but Kyon is the main character, in my opinion. I mean, the whole Disappearance arc was about Kyon, not Haruhi.
In rating the Haruhi characters in order of creepiness, I made Itsuki first (for having that smile on 24/7), then Yuki (not because she's an alien, but because she's so...omniscient), then Haruhi ("I'm bored" leads to "END OF THE WORLD"), then Mikuru (only for technicalities; she can SEE time-quakes), then Kyon (annoying but normal).
As for ships, I'm somewhat of a Yuki/Kyon, although since there really isn't much evidence as I can see (like I said, I didn't read in detail), I can't be too lovey-dovey like the other anime ships. (I might be a Mikuru/Kyon if you push me.) I'm also Parallel!Haruhi/Parallel!Itsuki, as if it hadn't been for the whole *incident*, they would be together. (I said nothing about the actual Haruhi and Itsuki.) Maybe...Parallel!Yuki and Kyon?
...no, too many fanfiction writers took that. Still, it's something to consider.
Haruhi/Kyon is an anime/manga fabrication and is ignored by me. In the light novels, Kyon specifically states he's aware of Haruhi acquiring and dumping boys at the speed of light, and it might be a good thing if she starts dating someone because it'd be easier on him and Itsuki.
You know the Yuki-is-in-the-Lucky-Star-cosplay-cafe-and-is-looking-for-Haruhi-in-an-alternate-reality theory? I might write about that.