Review last movie you've seen ==> Present perfect
Review last movie you saw ==> Past tense
The second is the correct one, bro.
Salam.
I'm not as good as bro roderick in grammar, nor i can explain exactly why, but i think it's more natural to say either "Review the last movie(s) you saw" or "Review the movie(s) you've see".
Using the word "last movie" indicate that it happened recently and we are emphasizing that particular time frame --> thus past tense is used.
Bro roderick, CMIIW pls...