Night of the Living Dead= A+
Dawn of the Dead= A
Day of the Dead= B+
Land of the Dead= C+
Diary of the Dead= D

Night of the Living Dead - A
Dawn of the Dead - A+
Day of the Dead - A-
Land of the Dead - C
Diary of the Dead - B

Night - A+
Dawn - A+
Day - B+
Land - C
Diary - C-

Night - A+
Dawn - N/A
Day - N/A
Land - D
Diary - N/A

Night: A+
Dawn: B+
Day: A-
Land: C+
Diary: N/A

Since I'm sure more than 9 of us are familiar with the franchise, I'll leave Romero's Dead open for grading for another 10-12 hours, then we'll move on.

Night - A-
Dawn - A+
Day - A-
Land - B+
Diary - C-

Night - A +
Dawn - A +
Day - A +
Land - B -
Diary - B

Night - A +
Dawn - A -
Day - (haven't seen)
Land - C
Diary - C+

What? you haven't seen Day Of The Dead?!

All these are A+ for me except for Land which I give a C and Diary which I give a B