Of all the relationships on The Big Bang Theory, perhaps one of the most charming and hilarious is the relationship between Penny and Sheldon Cooper. The two seem to run hot and cold with one another, but throughout the course of the show, Penny and Sheldon seem to stand up for one another almost as much as they torment each other.
Sheldon has rescued Penny a number of times. When Penny slips and falls in her shower, injuring her shoulder, she begs Sheldon to take her to the hospital. He eventually consents and drives her to the doctor and then back home again. When they arrive back at her apartment, Penny and Sheldon exchange a funny conversation:
Sheldon: Now remember, you were given powerful pain medication and a muscle relaxer, so don’t operate heavy machinery, and try not to choke on your own drool.
*Sheldon is is about to leave.*
Penny: Wait! You have to help me get into bed. (laughs) “Sheldon has to help me get into bed”. Bet you thought I’d never say that!
Sheldon: Yes. Charmed, your drug-addled candour knows no bounds.
*Sheldon follows her to her room after shutting the door. He pulls down the covers to help Penny into bed.*
Penny: You know people think you are this weird robot man who’s so annoying all the time and you totally are. But then it’s like that movie Wall-E at the end. You’re so full of love and you can save a plant and get fat people out of their floaty chairs.
Sheldon: That’s a fairly laboured metaphor but I appreciate the sentiment behind it.
Penny: Sing ‘Soft Kitty’ to me.
Sheldon: ‘Soft kitty’ is for when you’re sick, you’re not sick.
Penny: Injured and drugged is a kind of sick.
Sheldon: (sitting on the bed next to her) Soft Kitty, warm kitty, little ball of fur…
Penny: Wait wait. Lets sing it as a round. I’ll start. Soft Kitty, warm kitty, little ball of fur… *Sheldon doesn’t join in.*
Penny: So that is when you come in. I’ll start over. Soft Kitty, warm kitty, little ball of fur… Still nothing from Sheldon.
Penny: I’ve got all night Sheldon. *She starts again.*
Penny: Soft Kitty, warm kitty…
Sheldon: Soft Kitty, warm kitty… *They both sing the entire song together.*
When the characters all come back together at the start of season three, it is Penny who stands up for Sheldon against the other guys, including her boyfriend Leonard.
You can watch that exchange here. They may pick at each other to the point of extreme annoyance, but all in all, Penny and Sheldon have a special spot in their hearts for each other. And fans would love to see the two as a couple, but the likelihood of such a match up is slim to none; Penny and Sheldon are best suited for one another as friends.