An overview of some reviews that made good points (and NOT just entertaining). Hopefully, these can help guide and focus your thoughts when assessing a fic.

And yes, they are all video-game reviews, for most of the book reviews I read tend to focus more on the subject matter rather than the book itself. I've tried to isolate the bits which are most relevant to writing.

Zero Punctuation
Metroid: Other M (2:20 – 3:30). Characters – Inconsistent characterization.
Kane and Lynch 2 (3:30 – 4:10). Characters – Irrational character behavior and inconsistent characterization.
Aliens: Colonial Marines (0:40 – 1:40). Plot – Taking excessive liberties with canon.
Red Faction: Armageddon (1:20 – 1:50). Characters – Excessively “wimpy” characters.
Tomb Raider (4:00 – 4:50) and FarCry 3 (0:50-2:40). Plot – Ideas on believable character growth.

MrBtongue
“TUN: The Shandification of Fallout” (3:00 – 4:20 and 10:00 – 14:20). Plot – Ideas on creating believable worlds.

Extra Credits
“Skyrim’s Opening” (3:30 – 4:30, 5:50 – 6:40). Story – World introduction.
“True Female Characters” (3:00 – 6:30). Characters – Characterization.

(Feel free to add to this - although it might be more useful for each Justice League member to create a new post for his/her recommendations)