Oh, gosh. Oh, gosh. Oh...
Okay, this is in no order whatsoever, and I'm probably forgetting some. Oh well.
The Inseparable--I usually don't cry even at most of the death scenes, but this chapter broke me last time I read it. Not entirely sure why, but it did.
The Agony of Death After the Agony of Life--I love and hate this one, and is one of the few deaths that I do actually cry at. It's so heartbreaking and beautiful and painful and full and empty all at once.
Cosette Side By Side with a Stranger in the Dark--need I say more?
Between Four Planks--I love the Great Coffin Escape, period.
The Horizon that may be seen from the crest of a Barricade--The Enjolras Speech of Epicness
The Trap--Five words: "Would you like my hat?"
A Heart Beneath a Stone--Is it cheesy? Yes. Is it adorable? Also yes.
A Night Behind Which There is Day--Valjean's death scene
The Grass Covers and the Rain Effaces--The description of Valjean's grave
They're not chapters, I know, but I also love the Preface and Hugo's Letter to the Italian Editor.
That's not all of them, certainly, but that's a good start.