Critics and audiences were unanimous in their enthusiasm for Judd Apatow's Knocked Up. Its combination of screwball and crudity hit a nationwide nerve and slobbish slacker Seth Rogan's on-off romance with chic journalist Katherine Heigl, after she becomes pregnant following a drunken one-night stand, became the year's water cooler movie.

But why? It's crass, coarse and chauvinistic to a degree that would normally have had the usually trigger-happy PC brigade up in arms. The premise can only be described as a geek fantasy that objectifies women and reduces pregnancy and parenting to lifestyle choices. Moreover, it's far too long and becomes ever-more melodramatic as it lumbers through nine months of indecision and misunderstanding whose inevitability is exacerbated by the collapse of the seemingly perfect relationship between Heigl's sister, Leslie Mann, and her straying husband, Paul Rudd.

Hollywood used to excel at the comedy of sexual manners and the fact that a tradition inaugurated by such writers as Ben Hecht, Garson Kanin and Billy Wilder has descended into a post-Farrelly morass of smut and nerdish wish-fulfilment is the most depressing thing to happen to movies since George Lucas discovered special effects.

Having had the senses so relentlessly bombarded without recourse to intellectual stimulation, you may feel the need for a little fractal geometry. Surely boffins everywhere will be spending their DVD vouchers on a trio of fascinating films by Nigel Lesmoir-Gordon, which seek to explain how science and mathematics impact upon everyday life.

Clouds Are Not Spheres chronicles the life and work of Benoît Mandlebrot, whose discovery of the Mandlebrot set and fractal geometry transformed everything from medicine and meteorology to topography, economics and computer graphics, as sci-fi author Arthur C.Clarke explains in Colours of Infinity, which boasts a score by Pink Floyd's David Gilmour. Finally, the links between mathematics, the mind and the observable universe are explored by Sir Roger Penrose in Is God a Number?, whose discussion of the mystery of consciousness proved accessible even to someone who needed two cracks at O level maths.

There's more maverick thought on offer in Sydney Pollack's documentary Sketches of Frank Gehry, as the architect responsible for the Guggenheim in Bilbao and Disney's Concert Hall in LA waxes lyrical about art, commerce and compromise. And conflicting opinions also abound in Corneliu Porumboiu's hilarious satire, 12:08 East of Bucharest, as the recollections of two supposed witnesses to the fall of Ceausescu are challenged on a live TV show.

More myths surround Alan Crosland's The Jazz Singer (1927) than perhaps any film in screen history. But Al Jolson's singing and ad-libbed dialogue heralded the end of the silent era and launched the movie musical. Every serious film fan should see this creaky classic at least once.