Hannah Waddingham Keeps Mental List of Casting Directors Who Insulted Her

Hannah Waddingham's got a long memory ... 'cause she says she's got a mental list of the casting directors who shunned her over the years -- and, she's ready to get the last laugh. The actress opened up about her Hollywood s*** list during an episode of the "Sunday Sitdown with Willie Geist" ... telling the host there are a ton of people who wouldn't give her the time of day before who now want her in their…