Maybe Panther Town
In a recent episode of the WTF podcast, Bill Lawrence (the creator of Scrubs, Cougar Town, and Spin City) talks about how he hates the name of his show Cougar Town so much that he considered changing it this season. One of the main reasons he didn't is that DVRs aren't equipped to understand a name change, so the show would essentially lose any audience that had a season pass in TiVo.
Anyway, it got me thinking: Has there ever been a successful show that changed its name?