I really, really liked the inner conflict Javert had going on after being freed from captivity I thought Crowe managed to excellently convey the turmoil Javert felt at realizing his entire world view was flawed. While it saddens me I felt Javert's suicide was beautifully done, it was one of the few moments I could really sympathize with the character who was otherwise as cold and unmovable as the law which he represents.
I know exactly what you mean. I never really understood those two scenes when I watched the musical (I guess it was just lost on me, since it was lasting soooo looong) but after the movie I thought Crowe really conveyed his conflict well enough, through more than song, to justify why he died.