The Big Bang Theory’s 10 best episodes

“The Proton Transmogrification” –

The lowdown: As they prepare for Star Wars Day, Sheldon (Jim Parsons) and Leonard (Johnny Galecki) learn Professor Proton (Bob Newhart, above) has died. When the Professor appears to Sheldon in 
a dream, he tells him he’s lost every man he’s ever looked up to. “Just make sure you appreciate those who are still there for you,” his mentor says.

Did you know? The greeting for May 4, Star Wars Day, is “May the fourth be with you!”

“The Barbarian Sublimation” –

The lowdown: After a run of bad luck, a down-and-out Penny (Kaley Cuoco) is introduced to the world of online gaming. She soon becomes obsessed with her new virtual reality. With half-eaten chips in her hair and no sense of what day it is, Penny is lost in the digital world – until 
she realises she’s talking to Howard online and snaps herself out of it.

Did you know? Penny becomes addicted to the game Age Of Conan 
– a fantasy-themed online multi-player role-playing game.

“The Precious Fragmentation” –

The lowdown: When the guys purchase an old box of movie props, they discover they 
now own one of only nine official The Lord Of The Rings replica rings in the world. The problem: they can’t seem to agree on who should take care of it. Cue Sheldon’s hilarious metamorphosis into The Lord Of The Rings character Gollum.

Did you know? This is the first episode 
of The Big Bang Theory to mention Howard’s (Simon Helberg) father.

“The Bath Item 
Gift Hypothesis” –

The lowdown: Sheldon is lost for words when his Christmas present from Penny (Kaley Cuoco) is a used napkin that belonged to Leonard Nimoy. He’s the actor who played Mr Spock in the original Star Trek series. After realising the actor has not only signed the napkin, but wiped his mouth with it too, Sheldon is spun out. “Do you realise what this means?” he yells. “All I need is 
a healthy ovum and I can grow 
my own Leonard Nimoy.”

Did you know? The napkin exists in real life. There’s 
even a photo of Jim Parsons holding it.

“The Birthday Synchronicity” –

The lowdown: Loved-up Howard and Bernadette (Melissa Rauch) finally welcome the arrival of their little baby girl, Halley. And they make Raj godfather – even though he blabs about the baby’s sex just before Bernadette goes into labour.

Did you know? Because Melissa is so short, she had 
to be regularly fitted for 
new fake baby bumps.

“The Justice League Recombination” –

The lowdown: Combine New Year’s Eve with fancy dress and what do you get? The cast of The Big Bang Theory dressed as characters from the Justice League. Look out for Raj as Aquaman and Penny 
as Wonder Woman.

Did you know? Neither Amy (Mayim Bialik) nor and Bernadette appear 
in this episode.

“The Comic Book 
Store Regeneration” –

The lowdown: When Howard’s mother dies unexpectedly, the whole gang prove just how amazing and supportive they are as a group of friends. This touching episode was a genuine tribute to Carol Ann Susi, the late actress who voiced 
Mrs Wolowitz.

Did you know? 
The show’s creators agreed not to recast Mrs Wolowitz.

“The Maternal Congruence” –*

The lowdown: When Leonard’s mum, Beverly (Christine Baranski), casually announces she’s divorcing Leonard’s father and that Leonard’s childhood dog has died, it seems things can’t get much worse. But it soon becomes clear Sheldon has known the news for months. While we all feel sorry for Leonard, what really makes the episode is when Beverly kisses Sheldon.

Did you know? Raj (Kunal Nayyar) has no lines in this entire episode.

“The Adhesive Duck Deficiency” –

The lowdown: When Penny slips 
in the shower, Sheldon takes her to hospital – and also gets her back home after she’s had a few too 
many painkillers. While he’s tucking Penny into bed, she asks him to sing “Soft Kitty”, and the two harmonise in a beautiful rendition.

Did you know? “Soft Kitty” is so popular with fans, the cast is often asked to sing it during live panels.

“The Staircase Implementation” –

The lowdown: When Leonard and Sheldon first move in, Leonard grows tired of Sheldon’s antics – so he invites the guys over to witness an experiment. But when things go wrong, Sheldon saves Leonard’s life.

Did you know? Sheldon and Leonard fly a flag in their kitchen bearing the Löwenbräu beer logo.