"Love means never having to say you're sorry" (Love Story)
"There's been a murder here and SOMEBODY'S responsible!" (Plan 9 From Outer Space) Actually, that line is pretty hilarious.
"His God IS God" (Yul Brynner's Rameses in The Ten Commandments)
"NOOOOOOOOOOOOOOO!!!" (Darth Vader upon hearing of Padme's demise in Revenge of the Sith)
"Dad???" (Sofia Coppola's totally deadpan response after being fatally shot in Godfather III)
"Trauma causes pain" (Famke Janssen in Hide and Seek) No duh.