Another one is MIN and MAX ignore NULL values, which make for some interesting rollback scenarios.

I also swear I have seen a gotcha involving UPDATE WHERE IN and not throwing an error where it should have, which is why I always quadruple check my update statements, but I wasn't able to reproduce it and couldn't find any information online. I haven't seen the issue in so long I forgot what it was, but it would update all rows in your table even if your WHERE clause was proper.