- derivative work.
I might as well read the original or something else altogether.
- satire based on specific work, e.g. spoofs of Tolkien or whatever. I am picky with humour, and if the humour just stems from ridiculing something else, I can only bear it for about 20 minutes, not a whole novel.
Other genres I will probably pass, but usually stay away from:
- fantasy based on D&D type tropes
- military SF or hard SF without aliens and/or meaningful speculations about the future
- urban fantasy that is actually paranormal romance
- the flowery prose of 1920/30s pulp story, which I will only read/ listen to if they are classics you should know in the genre
OTOH, I did read everything by Stephanie Meier (spelling?) just so I can say "I know it sucks, I actually read it"