We're Having a BABY
EPISODE #45: LUCY IS ENCEINTE
In this episode, Lucy finds out she's going to have a baby, but trying to tell Ricky about it is very difficult when she is constantly interrupted. She finally devises a plan to tell him at the club in front of the audience, which ended in a very touching moment.

This episode was an "I Love Lucy" landmark in a sense that it introduced what would be the presence of 'Little Ricky', the new character in the series, and it also caused a lot of interesting racket in the television and entertainment industry, as far as the issue of 'pregnancy' was concerned. The word 'enceinte' was used in order to replace 'pregnant' in the Latin language. The introduction of the birth of little Ricky lead to more extravaganzas in the show's plot.

The BABY is Born
EPISODE #51: LUCY GOES TO THE HOSPITAL
When the time comes to leave for the hospital, Ricky, Fred and Ethel get so excited that they are more disorganized than Lucy. Ricky suffers from the news and becomes tired. He finds out that his new opening starts that same night, and he will not have time to wait at the hospital. When Fred calls Ricky, he rushes off of the stage in the middle of a number and goes straight to the hospital to see his newborn son, 'little Ricky'. 'Lucy Goes to the Hospital' is probably the most important episode in the entire series.
-> While 29 million television viewers in the US watched the inauguration of the President in January of 1953, 44 million watched this "I Love Lucy" episode. It even beat the inauguration on television!

It's So TASTY, Too!
EPISODE #30: LUCY DOES A TV COMMERCIAL
In the scene where Lucy does her promotional extravaganza on television for 'Vitameatavegimen', she swallows an extensive amount of the substance and falls under a heavy spell. Becoming drunk and ill, she continues to advertise the product until she is swept under the power of this strong substance and makes an outrageous performance as she continues.

This episode is an absolute favorite among many "I Love Lucy" fans, and is a landmark episode for the series, as a vast majority of merchandise is focused on this scene.

SPEED it UP a Little!
EPISODE #39: JOB SWITCHING
The episode 'Job Switching' introduced the second season of "I Love Lucy" and contained one of the most memorable and most loved scenes, as Lucy and Ethel strive to survive at the conveyor belt in a candy factory.
This scene is a definite favorite and is hilarious in capturing Lucy's expressions as she struggles to hide loads of chocolates and maintain a steady position in order to keep their jobs.

Harpo
EPISODE #124: HARPO MARX

Amidst their luxurious stay in Hollywood, Lucy is confronted with Harpo Marx as she attempts to entertain her long time friend from New York, Carolyn Appleby, by introducing her to movie stars. Lucy thinks everything will be wonderful until she discovers [from Ricky, of course], that there will be no movie stars for her to use at this time. Ricky then feels bad and bumps into Harpo Marx. He sends him up to the suite, but Lucy has already dressed up as Harpo, ready to entertain Carolyn. In this episode, Lucy and Harpo perform a wonderful comedy sketch.

California, Here We Come
EPISODE #110: CALIFORNIA HERE WE COME
This episode brought forth a new and exciting adventure for the characters of "I Love Lucy" and would introduce a series of celebrities and special guests throughout the show. Setting off to California, Ricky is anxious about making a new picture and beocming a celebrity, Lucy is excited about meeting celebrities and to associate with showbusiness, and the Mertzes are so happy to be able to travel along with their best friends.

Grape Stomping...
EPISODE #150: LUCY'S ITALIAN MOVIE

While in Italy, Lucy has been offered a role in an Italian movie. Assuming that the title of the film "Bitter Grapes" is related to a traditional wine making source in Italy, she attempts to 'soak up local color' and gets herself into trouble while doing so.

Lucy the Ballerina
EPISODE #19: THE BALLET
Lucy tries to get into Ricky's act, as they need a ballet dancer for the show. Trying hard, she takes ballet lessons, but messes things up a bit! She then discovers that a clown act is needed as well, but when she ends up at the show, ballet ends up being their main priority!

Lucy's Big Break in Hollywood
EPISODE #116: LUCY GETS IN PICTURES

When Lucy is glum about not getting in to the picture business while in Hollywood, Ricky finally gives her an opportunity, but certain things, especially a large hat, manage to mess things up a little, and the role she got was smaller than she expected.