4. Ann Veal - Arrested Development
While most television shows on this list had to recast out of necessity, because an actor left for another project or wasn't right for the part anymore, Arrested Development turned it into a running gag. What's brilliant about the fact that they recast Ann is because that's her whole character. She's so forgettable that it doesn't even matter if she's played by two different actresses, because no one even looks twice at her. In fact, the creators originally intended for Ann to be portrayed by a different actress every time she appeared on the show, but as it stands they only used Alessandra Torresani and Mae Whitman. While Torresani was featured in Ann Veal's debut, Whitman took over the role and continued on through the entirety of the show's run. Which is probably just as well, because Torresani eventually grew up to be a Maxim girl and Whitman, while undeniably adorable, possesses more of an Everygirl quality needed to make the Ann ("Her?") character work.