Love Actually is a feel-good tonic that would lighten the load of the heaviest cynic. But one has to be concerned about writer/director Richard Curtis’ well-being as a filmmaker when it’s over.

Every idea for an ending possible is crammed in, like the stuff that wouldn’t work properly in Four Weddings and a Funeral and Notting Hill. It’s enough to make you wonder if the guy’s got anything left for another film. Heck, love even saves Britain from being perceived as a pushover in international relations.

Most other romantic comedies would end with the funeral retrospective by way of the Bay City Rollers, the doorstep confessions of love or the extravagant Christmas pageant. This, of course, is all before not one, but two conclusions at Heathrow Airport, and the impromptu song to interrupt a wedding comes about 10 minutes in. Choppy, sloppy and goopy, that wedding bit really rankles. It’s edited and shot poorly, drips with annoyingly abstract emotion and we’re not sure who the heck anyone is.

Thankfully, it’s one glaring moment in what is otherwise an utterly charming, classy and uproarious work of romantic hopefulness. As pollen counts rise in late summer, so does romantic pixie dust in the winter. Love Actually sees how it inspires moments of temporary bliss and / or insanity, and how those moments can, or cannot, become permanent.

Set in London and starring nearly every great ’cross-the-pond actor and actress working today, Love Actually tells so many stories of intertwining infatuation that it can be overwhelming at times. Some of the connections are tenuous at best, but none of the storylines drags the film down.

Those that are shorter are best left more incidental — porno movie stand-ins making romantic small talk, the best man in love with the bride and a fed-up British guy who flies to America to score by virtue of his accent. But the five that take main stage prove to be so for a reason.

A cuckolded mystery novelist (Colin Firth) gets linguistically tongue-tied as he falls for his Portuguese maid (Lucia Moniz). Newly widowed Daniel (Liam Neeson) aids his young stepson, Sam, with his infatuation with an American girl in his class. Emma Thompson stars as a devoted wife and mother coping with her husband’s (Alan Rickman) infidelities that are definitely emotional and possibly sexual.

Then there’s Hugh Grant as the newly elected British prime minister who falls for one of his office staffers (the lovely Martine McCutcheon). And the sole American, Laura Linney, plays a magazine designer whose family responsibilities get in the way of a burgeoning romance with an office hottie.

Through all of this runs a story about a man seemingly in love with no one but himself — aging rocker Billy Mack (Bill Nighy). Mack has shamelessly altered the classic “Love Is All Around” into “Christmas Is All Around.”

He knows it’s crap and spouts questionable content in the countless interviews he gives on television. Imagine a brutally honest — and intelligible — Keith Richards. With fantastically cynical rants delivered in deadpan style, Nighy almost runs off with the film single-handedly. His final scenes with his manager are nicely understated.

Love Actually relies heavily on the romantic-comedy game plan of reaction shots, sometimes set to easy-to-swallow pop songs. But in the hands of this heavy-hitting cast, the standard becomes sublime.

Buoyed by Sam, Neeson’s emotional outbursts throughout have an uncanny power. Linney is great in her fussbudget moments when she blows opportunities and capitalizes on them. Thompson’s ultimatum speech to Rickman is outstanding. And Grant, again ridiculously good without even trying, dances to The Pointer Sisters’ “Jump” after a press conference where he makes a strong political statement doubling as a gesture of affection.

Love Actually coasts so effortlessly on its goodwill, even through all its false endings, that its nearly two-and-a-half-hour running time flies by. And when it comes to the real-deal conclusion, Curtis displays the same command over it that he gave to his other screenplays.

It’s a lush, winning film that, even if it only makes you think differently about mistletoe until just after Christmas, will have done the trick.