The Big Bang Theory’s funniest episodes

The antics of Leonard Hofstadter, Raj Koothrappali, Howard Wolowitz and a certain Sheldon Cooper have warmed hearts across the world. Bernadette Rostenkowski and Amy Farrah Fowler complete Chuck Lorre's merry band of scientific misfits, whose every equation and formula seems to fly straight over the head of the Cheesecake Factory's very own, Penny. The poor lass.

These loveable nerds are just looking to fit into the real world. Well, everyone except for Sheldon that is. He just wants to be left alone with science.

Having now amassed well over a hundred episodes, and with no end in sight, it's time to celebrate 'The Big Bang Theory' in all of its glory.

Here are the 5 greatest episodes of 'The Big Bang Theory' that you need to have watched in order to call yourself a true fan. Don't worry, you can leave your scientific calculators at the door.

The Staircase Implementation - Season 3, Episode 22

By this point in the series, every viewer had developed their own theory over how the cosmos had lined up in order for Sheldon and Leonard to end up living together. The Staircase Implementation fully explains how their relationship was formed, and there is even a whole host on in-jokes that revolve around the Nintendo Gamecube, Leonard's love for a Korean spy and Joss Whedon's Firefly.

The Bath Item Gift Hypothesis - Season 2, Episode 11

Sheldon's abnormal social behaviour often leads to him coming across as rude. After finding out that Penny plans to buy him a Christmas present, the scientist/robot struggles to figure out the appropriate gift to remunerate her with. When it transpires that her offering is a signed napkin by Leonard Nimoy, he becomes overwhelmed and gives Penny the greatest gift of all - a hug from Sheldon.

The Panty Pinata Polarization - Season 2, Episode 7

Howard and Raj finally had a chance to shine in this season two corker. Using their vast scientific knowledge, and a shed load of expensive equipment, the duo were able to calculate where the America's Next Top Model's mansion was located. And then, posing as cable guys, Raj and Howard finally enter the scantily clad abode and are able to live out their dreams.

The Nerdvana Annihilation - Season 1, Episode 14

Early episodes of 'The Big Bang Theory' revolved around Leonard's struggle to seduce Penny, whilst appeasing her nerdish desires. In The Nerdvana Annihilation, Leonard and the gang buy and share a full-sized replica time machine from the 1960 film, The Time Machine. But when the installation of the bulky object causes Penny to miss a shift at work, she erupts at the foursome and causes Leonard to reconsider his geeky ways.

The Robotic Manipulation - Season 4, Episode 1

Poor Howard. Before settling down with Bernadette, he really was just one massive pervert. So much so that he even looked to use a robotic arm as an accessory tool for masturbating. Surely the Scientific community wouldn't look down too favourably on such experiments? However the true gem of this episode is Sheldon's new friend, who is also a girl, Amy Farrah Fowler. Having made her debut at the end of the third season, she truly arrived in this episode and would later go on to become an integral member of the gang, helping to propel the series through some jitters later in the season.