Kyon's feelings for Tsuruya: Physically attracted, certainly. She's hot. She's interesting to him beyond that if only due to her near superhuman perceptiveness, combined with her complete willingness to not get involved. She's the anti-Haruhi in that respect, which has got to make him more attracted on a certain level, but I think they have the makings for good friends much more than anything romantic.
Tsuruya's feelings for Kyon: Interesting. He's the eye of the storm, in her eyes, making her probably the one character in the series whose point-of-view most closely matches that of the readers, despite the fact that Kyon narrates. She keeps her feelings close to her chest, but is not above a little flirting here and there. I think she could eventually have romantic feelings for him, but not at this point.
Kyon x Tsuruya likelihood? Low. She's clearly the dark horse of the four main female characters, but as SHUFFLE! taught us, never count the green-haired senpai out. She'd certainly be my choice, were I in Kyon's shoes.
Kyon's feelings for Mikuru: Physically attracted to and beyond the point of infatuation. Cares for her a great deal (moreso for small than big), but sees her as unattainable due mostly to her attractiveness, her intrinsic impermanence (both from her higher school grade and her future origin), and (for different reasons than Mikuru, due to his thickheadedness) Haruhi's wrath. Is also somewhat scared by Mikuru (big) and might be trying to do something about her. Perfectly happy to protect Mikuru (small) and put her up on an unattainable pedestal, because it's safe.
Mikuru's feelings for Kyon: One of two possibilities. One, she's madly in love with him, borne from her admiration for him as a historical figure (in her time) and his not completely non-existent charms, but she's forced daily to remember that for her moreso than for him, a relationship is unattainable, if for no other reason than it might remove her from existence. Or two, this is all a big charade on her part to toy with his feelings to get the result her superiors want. It's a little dark for this series, and a militantly Kyonist opinion (which I don't share), but the groundwork is there for the possibility to exist.
Kyon x Mikuru likelihood? Low, without massive changes to the plot. She (small, at least) is going to be leaving this series eventually, probably some time before the end, and her leaving will be so sad as to make the end of that one episode of FMA (you all know which I mean) look like the funniest episode of Keroro Gunso. It's just not meant to be. Maybe Kyon'll get lucky and get a piece before that happens... Just kidding.
Kyon's feelings for Sasaki: Good Friend. Maybe he has deeper feelings hidden underneath, but if so, he doesn't know they're there. And the presence of the Dark SOS isn't helping. Depending on the events in Vol 10, we may see something grow in the future, but I doubt it.
Sasaki's feelings for Kyon: Unclear. She may be even more emotionally stunted than Yuki, because Yuki at least has an excuse. She's emotionally immature, is far too self-deprecating, and, most tellingly, her omnipresent, vacant, dead Closed Space just creeps me (and Kyon) the hell out. She may be more interested in Kyon than in any
other male, but is that really saying anything?
Kyon x Sasaki likelihood? Short term? Mid-to-Low. Possible depending on the events in the β timeline of Volume 10, but nearly impossible in α. Long term? Zero. These stories are "The xxxx of
Haruhi Suzumiya," not "...of Sasaki Whatshername." There's a good chance "God" put her here only to be the love rival that every anime/manga/light novel heroine worth her salt has to face at least once, and she's not doing a very convincing job in that part so far. Miyokichi has had better buildup.
Kyon's feelings for Yuki: Quite a bit more than he's willing to admit, I'd bet, but conflicted. He trusts her implicitly, but there's still that little niggling bit of doubt, that worry that she's going to go "Disappearance" Yuki on him again or that the IDSE might decide to reformat her into the Ryoko File System, that makes him keep his distance. He's very protective toward her, even moreso than for Mikuru, for those reasons.
Yuki's feelings for Kyon: As strong as they can possibly be for a being who isn't supposed to have them. And therein lies the problem. She isn't 100% clear on the
concept of love, much less how to act on it. The one time she tried, she almost killed him, and it caused her to institute some pretty draconian safeguards (some of which I'm betting we haven't yet seen) to make sure she doesn't do it again. She's the only character in the series that we can safely, unequivocably say is "in love with" Kyon, and it scares the s**t out of her.
Kyon x Yuki likelihood? Fair. The only character besides Haruhi that can be said to have anything but a remote chance at Kyon, which is not surprising, as she is the only SOS member outside of Kyon and Haruhi to show any real character development, and in many ways has shown more than those two. Also, as Haruhi has shown strong protective feelings for her, she's somewhat safe, in the respect that a relationship with her would probably not end the world. It has been said that she is the author's favorite, and she is certainly the sentimental favorite, because everyone loves a robot love story. These
are the stories "of Haruhi Suzumiya," but last minute switcheroos and "favorites" coming in second are not unheard of in the harem genre...
Kyon's feelings for Haruhi: Definitely attracted both physically and emotionally, but she scares the crap out of him, and annoys him to no end. Despite the fact that he has kissed her, he tries to convince himself that it was only to save his own skin, and if he keeps it up, may eventually succeed. I don't think he'd turn down a second chance, however.
Haruhi's feelings for Kyon: She wants him. Bad. Only problem is, she's emotionally insecure and immature (I'm seeing a pattern), and can only resolve those feelings in aggression, denial, and depression (melancholy, if you will). The question is, what is more horrifying? Her reaching emotional maturity and facing her love of Kyon
after she finds out her abilities, or
before?
Kyon x Haruhi likelihood? Fair-to-High. She is in the title, after all. Plus, she's the
Tsundere, which is like MVP and Batting Champ rolled into one. She needs a little more maturity (of course, so does Kyon), but I can see a "GOOD END" in her future (if anyone is going to get one). But that's only the destination. The real story is in the trip there.