When Data died in Nemesis.
I dont know how I felt about that. I was sad because data is by far my favorite character, but then all that crap with B4 kind of sullied the whole thing, i left the cinema is a very strange mood.
It was a strange one, you're spot on. But before the moment with B4 singing 'Blue Sky' there was the moment when Data said goodbye to Picard. The crew crying over his death was another tough one to watch. I think that when Geordie followed Data to the forcefield, he knew he wouldn't see his best friend again.
As sad as it is, even typing this out gives me a lump
I'm a bit of a purist and as such, I was pretty gutted that they destroyed the Enterprise-D as well. It led to me never really taking to the Enterprise-E. But when Data blew up the Scimitar whilst on it, that was the worst I've ever felt watching a TV show or movie.