WHY DO all the decent men turn out to be gay? It's the common lament of the unattached Nineties woman, and a social question that director Nicholas Hytner attempts to answer in The Object of My Affection (15). Casting Jennifer Aniston as your heroine might seem like a bad move for a director with anything vaguely serious or complicated to say: Aniston's last vehicle, Picture Perfect, was just another turkey in the flock of disastrous attempts to turn the cast of Friends into movie stars. But in Hytner's movie, her aimless ditziness is rendered workable by the combined effect of her classy co-stars (Alan Alda, Allison Janney, Nigel Hawthorne) and a script that's gagged to the nines.

Aniston stars as Nina, a pregnant social worker who decides to bring up her child with her gay flatmate, George (Paul Rudd, as scrubbed and well-behaved as a teenage Christian). For a while it looks like this relationship might work, that the film could offer a utopian vision of how the exploded elements of the nuclear family might rejig themselves into new and more complex forms. But soon things aren't going well - Nina falls in love with George, George falls for an aspiring actor, Paul (Amo Gulinello), and the movie ends up reinforcing the hetero/homo binary as enthusiastically as an Edwardian psychiatrist.

Following Rupert Everett (My Best Friend's Wedding) and Kevin Kline (In and Out), Rudd is the latest in a growing number of actors to play gay heroes in romantic comedies. They're an emasculated, fluffy bunch. They smile, they're kind to children, they join the female star in midnight heart-to-hearts over the Haagen-Daaz, and they perfectly accessorise with the bachelor-heroine's lifestyle. But they're more like glove puppets than real human beings. The sexual relationship between George and Paul makes Sesame Street's Bert and Ernie seem full of dirty passion. Rather than representing a radical liberalisation of he Hollywood product, these comfy gay heroes attest to our squeamishness about male heterosexual desire - which is now seen as too nasty or pathetic to be a fit subject for upbeat romantic comedy.

The supporting cast provide the most satisfying pleasures of Hytner's movie: Alan Alda reprises the bleary-eyed, yammering self-obsessive he played in Crimes and Misdemeanours - this time as a hot-shot publisher whose idea of a chat-up line is "I've got the galleys for the new Michael Crichton in the car". Allison Janney is Aniston's hard-as-nails stepsister, ever-ready to name-drop King Hussein, RuPaul or Steven Spielberg. And Nigel Hawthorne turns in one of the most sensitive performances of his career as a disappointed old theatre critic who discovers that the man he loves is having an affair. With his line, "Paul and I are currently meandering through some of the better Australian chardonnays," he somehow manages to conjure a whole world of fragile dignity.

Putting monsters in subway tunnels isn't the most original sci-fi concept, but play it with conviction and you'll have your audience screaming for their lives. Guillermo Del Toro's Mimic (18) does just that, pitting Mira Sorvino's glamorous entomologist against a brood of slavering giant 12-foot cockroaches. Del Toro has an acute sense of the hideous: these creatures scutter and chitter and rattle so horribly that they gave me flashbacks to the traumatic period I spent as school locust monitor. And try this on for nastiness - in order to cover the scent from a bleeding leg that's driving these insects crazy, Del Toro makes Sorvino rummage in the suppurating carcass of a dead bug and then smother herself and her companions in arthropod mucus. Deeply disgusting, divinely watchable schlock. My kind of movie.

As if to help critics move effortlessly from film to film, the opening shot of Palmetto (18) is a huge close-up of a cockroach. Volker Schlondorff's film is a noir thriller so hoary and old-fashioned that when the police characters start discussing DNA tests, it feels like an unwelcome anachronism. Judging by their disinclination to play it straight, Schlondorff and his cast clearly have little confidence in the plot's cliche- driven creakiness. The double-crosses practised upon the hero (Woody Harrelson) are so transparent that he has to place an overwhelming emphasis on his thick-eared stupidity - which, fortunately, is something well within Harrelson's capabilities. The women don't seem to be taking things too seriously, either: Chloe Sevigny waggles her weird, schoolboy-in-drag sexiness and Elisabeth Shue overacts herself into a gasping orgasm of untrustworthiness. There's the occasional outburst of wit - Schlondorff cuts from Sevigny's corpse fizzing in an acid bath to Gina Gershon massaging spaghetti down a plughole - but Palmetto feels like a pointless exercise in passing off iffy material as high camp.

There's a similar pointlessness about Mark Pellington's Going All the Way (15), the latest in a spate of American films set in the 1950s. Why, I wonder, is this happening now? This consumerist, conservative decade was far more resonant with the 1980s, when audiences flocked to Peggy Sue Got Married, Back to the Future and Dirty Dancing. These days, the period seems completely irrelevant. This, I think, is the reason why Pellingon's smalltown rites-of-passage story - despite many well-observed situations, a handful of creditable performances and a memorable scene in which the skinny, tongue-tied hero (Jeremy Davies) is caught masturbating onto a teddy bear by an evangelical ex- convict - is so soporific.

Girls' Night (15), Nick Hurran's intermittently effective feel-better film, stars Brenda Blethyn as a factory worker from Rawtenstall who simultaneously wins pounds 100,000 on the bingo and discovers she has an inoperable brain tumour. So it's off to Las Vegas with her sister-in-law Julie Walters, where she exchanges her Mo Mowlam headscarf for a Tammy Wynette wig, and goes flirting on horseback with wrinkly cowboy Kris Kristofferson - not remotely put off by his resemblance to a huge shrivelled breadfruit in a 10-gallon hat. The best gags come at Kristofferson's expense: he rumbles about his experiences in 'Nam and Blethyn exclaims, "Oh, I saw The Deer Hunter and it were awful." Other parts of the script are badly mismanaged, the worst mistake being screenwriter Kay Mellor's decision to shoehorn in some pseudoreligious bafflegab about how "we've all got the Angel in us", which cheapens the value of the common-sense observations she makes about coping with cancer.

Jacques Doillon's Ponette (PG) has a firmer grip on the mechanics of emotional trauma. It's a sensitive study of childhood bereavement, made remarkable by the fact that its central performance is given by a four- year-old actress. Victoire Thivisol has an uncanny facility for projecting distressed tinyness - her trembling lower lip is a heartbreaking sight. In real life, I imagine she uses it to get all the Jelly Tots she desires; in Doillon's film, she uses it to reduce the cinemagoer to a state of wracked, helpless pity. I'm not sure whether this is very healthy. No matter how many times you went to see the film, you couldn't make little Ponette any happier. Cinema can be cruel, sometimes.

And it can also be utterly absurd: in nonagenarian director Manoel Oliveira's Journey to the Beginning of the World (U), a nonagenarian film director (Marcello Mastroianni, in his final role) drives through his native Portugal with a group of colleagues, having Proustian reveries in front of trees. When other people would be playing travel Scrabble, they are having conversations of oratorical formality. Mastroianni compares the return of nostalgic memories to the movement of volcanic lava. Someone else compares the movement of volcanic lava to the war in Bosnia. "Sarajevo is happening all over the world," chips in another. "Apocalypse Now," remarks the driver, enigmatically. Then we get a few minutes of the view of the motorway from the back seat of the car, accompanied by urgent atonal thrashings on the piano. At the critics' screening, half the audience walked out before the end, and the rest of us sat there giggling, overcome by its transcendental silliness. I used to think of Mastroianni as a glamorous Vespa boy. Now I've seen this, I'm stuck with the recollection of how daft he looked gazing beatifically at a herd of Portuguese goats. Ahhh, how the memory of those goats returns like Sarajevan lava ...