Film Culture Commentary: Is It Always a Bad Thing When An Actor's "Always the Same"?

Read this, please.  No, it's not always a bad thing, though sometimes being way too predictable is boring.  I've said that Meg Ryan is always Meg Ryan in her movies -- the charming neurotic in all those romantic comedies.  Having said that, though, I love to watch actors who are virtuoso chameleons, who can disappear into their characters, who are unpredictable and can turn on a dime from being a terrifying stalker to a nebbishy detective to a romantic lead.  I'm talking about people like David Tennant and Sam Rockwell and Russell Crowe and Gary Oldman and Alan Rickman.  I would usually add Christian Bale, but I'm still mad at him after "Terminator Salvation" and "Public Enemies."