This is a great feature.  As part of today's SAG Awards Preview, Variety has a long list of "Actors on Actors," with many of the hottest names in the industry speaking up on some their colleagues.

In one of my favorites, Javier Bardem on Hal Holbrook, the "No Country for Old Men" star says Holbrook's moment in the truck with Emile Hirsch's Chris McCandless character is "one of the best performances [he's] seen."

Forest Whitaker talks up his co-star from "The Last King of Scotland," James McAvoy, calling the actor's "Atonement" performance "authentic," saying that when he tries to describe the portrayal to people, it "gets [him[ in [his] throat."  Josh Brolin, meanwhile, offers a humorous anecdote about the first time he met Ben Foster, and Foster pays it forward by calling Ellen Page's "Juno" portrayal a "flagship character for our generation."

There's plenty more, of course.  You can find the whole lot at Award Central.  Give it a look.