I just started a similar thread in the general forum. Talk about telepathy!
For me, the most emotional TNG moment that I can think of right now is Lal's death. It's so heartwrenching to see her develop the emotions that Data never managed to muster, only to end up overwhelmed by them. And through it all, Data is incapable of feeling the tragedy that is unfolding in his life. I loved how the rest of the bridge crew and, in the end, even Admiral Haftel, function as channels for the emotions that Data couldn't feel himself.