I'll second the Hanners/Marten relationship as being my favorite one in the strip; mostly because Hanners and Marten, for all their neuroses, are both arguably the most genuine and forthright folks in the strip with how they relate to others instead of themselves.
Heh, part of the reason QC is so good is that everyone sees a little part of themselves in a character. I am very much like Marten, completely ripe for taking abuse when it comes to myself, but blow up on a hair trigger if someone goes after my friends.
That said, Marten & Hanners turning into a full-blown friendship seems like a perfect fit for both of them. Marten is at his best when it comes to making himself better because someone else needs it, and Hanners is the perfect person to do that for. Innocent, naive, but genuine and doesn't have the "trying to read her" aspect that can frustrate Marten. WYSIWYG, and that's what Marten needs in his life. For Hanners, having someone like Marten able to start getting her spooled up and becoming more part of normal society is what she needs; someone she can trust to only have her best interests at heart, and do what it takes to make her happy and feel accepted.