In the TV series Wiseguy (1988) and the movies The Ref (1994), Swimming with Sharks (1995), The Usual Suspects (1995), L.A. Confidential (1997), and American Beauty (1999), Kevin Spacey seemed immune to the sentimental weaknesses of common human feeling, and in him it came across as heroic. He could be unlikeable, wrongheaded, corrupt, even sociopathic, but his ringing theatrical confidence made you want more of the same. (He had panache even when he played, or the character just pretended to be, vulnerable.) He was kind of stiff but physically imposing because his body was backed up by that sense of command and impenetrable attitude. No American actor had ever been more formidable in confrontations, and you didn't care if he was a good or evil knight, you just wanted to see the bullets bounce off his armor.
Spacey hasn't lost his skills but he seems to have lost his way. Of course, there were, and still are, limitations to what he's so good at. He was unremarkable as a conventional action-picture hero in The Negotiator (1998) because his heroism is essentially ironic, combative--contempt is the lightning that gives his monsters life. In addition, he's so much more verbal than physical an actor that he presents a figure of potency without eroticism. Which is to say he doesn't really work opposite women. (In The Ref he and Judy Davis compete against each other's high-comedy skills with amazing snap but they play a divorcing couple so the dissonance between them makes sense; they don't have to meld entirely. Click here for my full-length review.) He can be so enviably scary in conflict it's hard to imagine what he could relax into if he ever let his guard down. He's a magnificently skilled technician but more than slightly monolithic. That is to say, Spacey's undeniable charisma is undeniably cold.
Not to mention, the sentimentality that refuses to stick to Spacey's surface is generally essential to stardom in American movies. I believe when he went after a wider audience in 2000 he did it out of a sincere desire to connect, to avoid being cast in concrete as the most impervious, rebarbative, isolated of men, however sensationally gifted. You can't blame a guy for trying something new, but nobody is given every kind of talent. This shouldn't be read as a manifesto in favor of typecasting, but some of the greatest movie stars had relatively limited ranges precisely because of the intensity of their personalities--James Cagney and Bette Davis are perhaps the clearest examples.
Toward the end of L.A. Confidential and about half-way through American Beauty Spacey's characters reform, become more like "us." And in both movies he's killed, as if the makers couldn't imagine what purpose a softened Spacey could serve. American Beauty also makes the mistake of justifying his extreme acidulousness--it's his wife's fault, society's fault, suburbia, homophobia. Once he burns past his disdain he goes gooey--and he hasn't looked back since.