BSG here and there (please skip The Plan... ugh), but LOST takes the cake. *spoilers* - Edit 2
Before modification by Zalis at 20/06/2010 10:23:30 PM
In both series, I blame the music. I cried the most in BSG when Roslyn died. In LOST, I got misty a lot when they'd pump up the sad music, but didn't *really* get nailed until main character deaths and the final ep.