The "water cooler" shows of the moment are Desperate Housewives, Lost and Big Brother 5. The Big Brother launch created an enormous buzz with its secret annexe, crazy twin swap, dwindling prize money and a contestant who behaved a little like Sharon Stone in Basic Instinct within the first hour.

There's no denying that reality TV has produced some remarkable water cooler moments over the past few years. For starters we've seen Johnny Fairplay's "Grandma's dead?" ruse on Survivor; Omarosa's "n-word" accusation on The Apprentice and Bachelor Bob's pash-and-dash behaviour on The Bachelor. But in ye olde days it was television dramas that got people gasping in front of the box.

In 1980, 350 million people across 57 countries tuned in to discover one thing. Who shot TV's nastiest, Stetson-wearing oil-baron - JR Ewing? Dallas's leading villain got the bullet in March, 1980, but in a stroke of script-writing genius the killer wasn't revealed until November. So for eight months viewers were glued to their sets.

Who shot JR? T-shirts, bumper stickers, coffee mugs and endless speculation followed. And not just in the US. When the film canisters containing the "killer-revealing" episode were flown to the UK to be aired, an armed guard accompanied them from Los Angeles to Heathrow. (For the record, JR was shot by Kristen, his sister-in-law.)

A decade, and some industrial strength cling wrap, later and a new murder was on everyone's lips. When the body of teen queen Laura Palmer was found "wrapped in plastic" in Twin Peaks, it started a television obsession.

Twin Peaks was quirky and compelling all at once and David Lynch's drama hooked viewers from around the world. The more viewers found out about the death of Laura Palmer, the more weird things they learnt about the people of Twin Peaks. Everyone had a secret, from the Log Lady to Agent Dale Cooper and his love of cherry pie. It was a clever tactic - one now used in Desperate Housewives - that kept viewers hooked on the show until the end. (Although, let's be honest. It was a weird ending concerning BOB and Leland Palmer.)

Of course, not all "water cooler moments" involve dead bodies. Sometimes they involve slappers and psychopaths. In the mid-'90s, tongues started wagging when no sooner had Brenda Walsh said "O revoyre mon cherries" (Beverly Hills French) and left for a summer holiday in Paris, than her boyfriend Dylan and her best pal Kelly started doing the funky-monkey in the swimming pool.

A few years later and fans gasped in horror as zipper-head Dr Kimberly Shaw de-wigged in the mirror and then attempted to blow up the apartment complex on Melrose Place. And on Friends, millions of fans said "d'oh" when Ross said, "I Ross, take you Rachel" during his wedding. Unfortunately, he was marrying Emily at the time.

In 2003, when long-running soapie Days of Our Lives started to fall in ratings, the scriptwriters obviously knew that they had to do something BIG to bring back the viewers. Considering that each cast member had at some point had amnesia, been held hostage on a desert island, befriended Satan, been mistaken for European royalty or reincarnated as Roman Brady, there was only on solution. Kill everybody.

The Salem Serial Killer storyline took months to unfold as nine of Salem's favourite residents were bashed, slashed or killed with doughnuts by none other than Marlena Evans Brady Evans Brady Brady Black. It was the storyline that got everyone talking in the US but soapie-rage followed when viewers discovered that none of the victims were really dead. They were all being held captive on an island - surrounded by a force field - that was a replica of Salem. What are the chances? Actually pretty high in Salem because since the show began, more than 30 characters have been brought back from the dead.

Not to be outdone, Australian soapies have had some corker storylines over the years. During the '70s, Number 96 had the Knicker Snatcher, the Pantyhose Strangler and the Hooded Rapist storylines to lure viewers. More recently, we've seen Home and Away's Summer Bay Stalker revealed. Over at Ramsay St, the "when's Karl going to find out he's not the father of Izzy's baby?" storyline saw the ratings rocket.

As for me, I'm holding out for that quintessential Play School cliff-hanger. Still bitter about being ditched from the show, Hamble (the Jan Brady of the toy box) seeks revenge on Jemima a-la-Single White Female.