Actors who are able to play a wide variety of roles are generally considered more skillful than those who play a similar type of roles, however brilliantly. This is, I concede, not without justification and that's why I think Meryl Streep is a much more skillful actor than Isabelle Huppert. She can be an over-the-top villainous boss in one film (The Devil Wears Prada) and right in the next film can break your heart singing a sentimental ditty about her late "mama" (A Prairie Home Companion). In contrast Huppert through her choice of roles (and more than that her choice of directors) has confined herself to a very specific character type: frosty, distant, irritable, edgy, contemptuous and full of inarticulable pain and despair (just to list a few). As she says in this interview, "But if I do have a stereotype, I am my own stereotype. It's nice to change but you cannot totally give up who you are, even if you have a big temptation to do so." Even when she is doing a different role, like in Francois Ozon's comic farce 8 Women, she is actually in fact doing a self-parody. It won't make sense or be funny to those who are not aware of the "Isabelle Huppert" persona.
In her interviews she is very forthright and clear about her conception of cinema, which is hardline auteurist. She believes that cinema is the expression of director's personality and subjectivity and an actor is just a tool which enables him to realize his vision on screen. She won't agree with it but I think if one takes a look at her body of work she herself comes across as some kind of an auteur, maybe an auteur by proxy because she chooses directors who are close to her own personality. Even her external appearance seems to be remarkably consistent. She does change a few minor things (like hair for example) but she mostly remains the same, most remarkably her pale and ridiculously freckled skin (I can't imagine any other actor who has more freckles on her skin than her). She never hides it under makeup and in fact directors often highlight this aspect of her appearance. As her proud husband in Patrice Chereau's Gabrielle says, "Paleness is one of her attractions."
I think the most important thing that distinguishes her from most other actors, specially female actors, is her absolute refusal to exteriorize emotion and inner feelings. Instead she just gives hints about it through her face, body posture and her voice. It is upto the audience then to think and find out what is going on behind that cold, distant face of hers and it is this which results in a level of engagement deeper than what most actors are able to achieve. It also helps since most of the characters that she plays suffer because of their inability to articulate their inner thoughts and feelings. It is often claimed by feminists that patriarchal cinema aestheticizes female suffering and turns it into a spectacle, in the process objectifying it. (I agree with the aestheticization bit, but I don't believe it necessary objectifies suffering.) She seems to be very conscious of this line of thinking and as a result the suffering female characters that she plays are far from aestheticized. She makes it impossible to feel pity for her characters, that most disposable and easiest of all emotions. Instead she gets deeper into the subconscious of the viewer bypassing the simple emotional identification that most actors aim for. She also avoids the cliched psychologizing that many actors and directors use to create character.
I have seen quite a few of her interviews and indeed it comes as a shock to see her as easygoing and jovial. Though if one looks closely the distance and the feeling of "I'm not really here" is almost always there. In her interviews she also says that she doesn't have any conscious "technique" that she uses. She also says that she never does any kind of research into her roles and the text and the director are the only sources of external information she has and on which she bases her interpretation of the role. The interview was actually in the context of her performance in the play 4:48 Psychosis written by British playwright Sarah Kane. Soon after writing it Kane committed suicide (she was 28). I haven't seen or read the play but it is actually written like a suicide note and performed as a one and half-hour monologue by an actor who has to keep standing at the center of the stage grounded like a tree. Huppert received lot of critical acclaim for performing in this role but when the interviewer asked her if she did any research on why Kane committed suicide and any other reading on suicide she denied doing any of these things. For her it is just the immersion in the text coupled with her imagination that enabled her to get close to something as extreme as the subjectivity of the author in 4:48 Psychosis. I personally find it hard to believe that one can intuitively immerse one's self in such extreme situations but then I really find acting one of the most mysterious of all artistic activities. (Admittedly acting isn't always artistic but with her it is definitely an exception.)
One can really go on and on writing and talking about her. Her oeuvre is simply one of richest of all contemporary actors and provides food for endless intellectual and emotional stimulation. I personally have had quite a few nightmares about her after watching her films, something I can't say about any other actor. I find her very unsettling and very disturbing - almost as if she knows some dark and really terrible truth and is hiding it behind her pale face.
Below is my own top 10 favourite of her films (from the ones I have seen so far):
The Piano Teacher (Michael Haneke, 2001): She plays an aging and repressed piano teacher who refuses to succumb to the seduction of a young admirer leading to extremely painful consequences. A very disturbing and depressing film, also a masterpiece.
Women's Affairs (Claude Chabrol, 1988): She plays an amateur abortionist in the Nazi occupied France with such chilliness that it sends shivers down your spine.
The Lacemaker (Claude Goretta, 1977): She was never more beautiful than in this film. She plays a young girl hopelessly in love but unable to articulate which is then mistaken for her dullness. Another painful and haunting portrait.
The Ceremony (Claude Chabrol, 1995): For a change she plays a flamboyant character, that of a psychopathic postoffice clerk who conspires to kill a bourgeois family with a murderous maid (played brilliantly by Sandrine Bonnaire in a Huppert-esque role)
Violette (Claude Chabrol, 1978): Based on a real story, she again plays an inarticulate teenager who plots to murder her parents to get money for her lover.
Loulou (Maurice Pialat, 1980): She plays a bourgeois wife who leaves her husband for a loutish man (played by Gerard Depardieu). She is again very beautiful in this film.
Madame Bovary (Claude Chabrol, 1988): Not really successful as a faithful adaptation, ironically because of Huppert's presence. Her Emma Bovary is much too deeper and complicated than the one in Flaubert's book.
Merci Pour le Chocolat (Claude Chabrol, 1999): If the sweetness of Hollywood Chocolat (with Juliette Binoche) had you puking this might be an antidote. Huppert has her own chocolate recipe which includes a dose of poison.
Gabrielle (Patrice Chereau, 2005): "Paleness is one of her attractions." A proud husband's life is shattered when one day her wife decides to leave him and then comes back.
8 Women/I heart huckabees (Francois Ozon/David O. Russell): As my one line summary might have indicated, these are not really what you would consider a "healthy" watching. So for a change these two light-hearted self-parodies.
The catalogue of the museum of modern art has more details about these and her other films. I want to see Malina which is based on the novel by Ingeborg Bachmann.
Some other interviews: from the guardian at the london film festival. A profile from Sight and Sound.