IDK, it generally takes a lot to make me cry. I think the last time that happened was when I was 16 and reading the novelisation of Star Trek: Generations. I was a big TOS fan and dealing with a lot of teenage angst at the time, and when I got to the part where Kirk died I just started absolutely bawling, lol.
The Time Travellers Wife. I was crying so much at one point I could barely read the words on the page, but at the same time couldn't stop reading!
Also, I know I keep banging on about the Chronicles of St Mary's series of novels, and for the most part they are funny and action packed adventure. But occasionally they also rip your heart out and stamp on it, and do a little evil dance on it for good measure. I seem to remember book 2 as being particularly guilty at making me cry in a public place, but several of the others have their moments as well.