Musings on Impersonation Acting

I just want to say a word or two or sixty about performances based on actual people. This year in the Oscar race there are a few people who are playing real people. Some, like Sandra Bullock are playing people who no one really knew before the movie. And some, like Meryl Streep and Morgan Freeman are playing people who we have a clear picture of in our heads. You can't get away with a shoddy performance as someone we all know.
There are two requirements, in my opinion, of playing a famous person on screen.

1. That you give a realistic and believeable portrayl of whomever the person may be. Adopting their mannerisms, speech patterns and looks in order to make us believe that you are that person.
2. (This is where many actors fail) To give us a believable picture of the parts of this person's life that we have not been able to see. To marry the impersonation with the human factor.

It is number two where I have seen the most actors fail. There have been numerous performers who have played famous people, many to Oscar-winning success. And many have failed. What they need is that human factor. We, the audience, need to belive that not only are you the person we have seen on TV or in the movies, but that you are the person we did not get to see. That is the point of the biopic, after all. To show us the person behind the persona.

Five Best Performances as Famous People

5. Cate Blanchett in I'm Not There

4. Michael Sheen in The Queen

3. Sean Penn in Milk

2. Drew Barrymore in Grey Gardens

1. Sissy Spacek in Coal Miner's Daughter

What's your favorite/least favorite biopic performance?????