The appeal of the enduring, mysterious Swedish star Greta Garbo, who made "I want to be alone" an essential element of her legacy, is chronicled by Mark A. Vieira with a meticulously researched account of the making of each of her 24 American films.

The Spanish-language Secuestro Express (Kidnap Express) addresses a disturbing social problem plaguing Mexico, Colombia and Venezuela: rampant, daily kidnappings. But Jakubowicz's style is hardly simpatico with social studies.

Werner Herzog is legendary for his exploits and encounters with madmen and his obsessive filmmaking. He has found, critics agree, a perfect subject in Timothy Treadwell, whose animal activism Herzog beautifully chronicles in Grizzly Man.

What the amazing documentary Murderball makes clear is that Mark Zupan, his teammates and their opponents can be as ferocious and as dazzling as Mad Max on the court in their souped-up, specially constructed chairs. Or off.