While I don't have any real deal breakers, I do have pet peeves.
I like RAW and not house rules. Part of this is my inner rules lawyer. But mostly it's that I know what to expect. It's the only real control I have in the game, especially with 5e. I love 5e because the rules are so simple that anyone can pretty much have system mastery after a little while. This is what I control vs. everything else the DM controls. To sit at the table ten sessions in and be told, "No, that's not the way that Force power works in MY universe" irks me. Thank you, DM, for invalidating my entire character.
As for Sage Advice, I have philosophical problems with it. Your job was to put together a coherent, clear rules source so that all I need when I sit down at the table is my PHB and some dice. I shouldn't need to memorize 3 million tweets and 30 pages of errata and FAQ in order to play. That just means you failed in the job you were paid to do. So Crawford and Mearls can give all the sage advice they want, but I'm not following them on twitter or checking the website each day for just what other rules they messed up. Adventure League doesn't even consider Sage Advice to be legal. They just had a thread over there crapping all over his recent Cutting Words ruling.