Not Mikuru and Kyon. I can't see that happening. It'd totally mess up the space-time continum, and all that... Kyon is his cutest around Mikuru, though, and vice versa.
Yuki and Kyon...hmm...I guess that's ok. I think Kyon brings out something in Yuki that people can't normally see...and Kyon can figure out Yuki's emotions better than anyone else. So maybe...
Haruhi and Kyon: undoubtedly the best couple, but I can't see that happening either

While Kyon sticks by Haruhi's side, listening to her no matter what circumstance, marveling her, and while Haruhi seems to look at Kyon's opinions very closely and wanting to only be with him, I think they get down each other's throats too much to be a couple. Not to mention, I don't think either of them are thinking of a serious relationship with each other. Going on dates? Kissing behind school (well, maybe not...)? I think that Kyon and Haruhi are better off as very close friends...
(Oh, and as for Itsuki and Kyon...I think that makes for a VERY good romantic comedy...

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