The two friends appear to have little in common. Miles is a depressive sad-sack, who is in his third year of failing to get over his divorce. Jack, on the other hand, is a blond, gregarious playboy; who is looking for a last week of fun before settling down to marriage.
Along the way, Miles tries to teach Jack about wine, while Jack tries to get Miles laid. He arranges a double date with Stephanie, a local wine pourer, and Maya, a waitress whom Miles already knows and admires. Gradually, these relationships develop, and Miles opens up to the possibility of finding love for a second time.
This romance may appeal more to male viewers than to women, as it matches the rather doughy Giamatti (Harvey Pekar in last year's American Splendour) with the dazzlingly beautiful Virginia Madsen. Nonetheless, it leads to one of the most romantic scenes of any recent film, when Miles tells Maya about a particular type of grape, which he describes as vulnerable, temperamental and thin-skinned, but worth the extra nurturing that it requires. It is clear to us and to the characters that he is really talking about himself, and Maya's response is suitably tender.
The film is based on a novel, and this background shows in the complexity and depth of the characters. Throughout the film, we feel that we like and understand these people, even though in many ways they are unappealing. Early on, Miles visits his mother, and steals some money from her drawer. In an average film, this would be a simple cue that Miles is a villain, but Sideways is more complex and forgiving: instead we learn that his mother knows about the stealing, and allows it, although it is a source of sadness and regret for both of them.
Paul Giamatti was unlucky not to receive an Oscar nomination for his touching and subtle performance, which betters any of his previous work. The whole cast are excellent, in fact, and I suspect Thomas Haden Church will probably win the Oscar in the Best Supporting category. Alexander Payne's direction is simpler and more effective than his previous film, the rather overrated About Schmidt.
The film also has the added bonus of being clear and detailed enough to actually teach us a little about different wines, which makes a nice change from the usual film-going experience, after which we can barely remember the characters' names.