Crafting a hit sitcom is tough work, but seems to have a winning formula that just can't be beat. The man has given the world some of the most popular sitcoms of all time, some of which include and none other than .

success can be attributed to many things, one of which is the show's ability to convey the dynamics between its lead characters. Had things gone according to plan, however, this would have looked a lot different, but a few changes turned the show into a classic.

Let's look at how this hit series almost looked a lot different.

'The Big Bang Theory' Was A Phenomenon

When looking at the most successful sitcoms of all time, there is simply no way that someone can gloss over what was able to accomplish during its time on the small screen. The series, which was created by the legendary Chuck Lorre, was a colossal success that left a permanent mark on television audiences.

Starring Jim Parsons, Johnny Galecki, and Kaley Cuoco, is the perfect example of a show that did all the little things right. The characters were brilliantly cast, the scripts were sharp, and the collective performance given in each episode elevated all of the show's finer elements. Once again, Chuck Lorre had crafted a smash-hit series that audiences loved.

might not be airing new episodes at this point, but thanks to streaming, it remains incredibly popular with fans, and it will be able to further its legacy as time goes on.

As we mentioned already, this show hit all the right notes, but early on, there were some changes that could have drastically altered the show's legacy.

It Almost Looked A Lot Different

Casting a show is tough work, and any changes to what is put in place can have a huge impact. Before perfect cast was put into place, there were some interesting names up for roles.

At one point, Macaulay Culkin was famously up for the role of Sheldon.

, "They pursued me for And I said no. It was kind of like, the way the pitch was, ‘Alright, these two astrophysicist nerds and a pretty girl lives with them. Yoinks!’ That was the pitch. And I was like, ‘Yeah, I’m cool, thanks.’ And then they came back at me again, and I said, ‘No, no, no. Again, flattered, but no.’ Then they came back at me again, and even my manager was like twisting my arm.”

Other names that found themselves up for roles include John Ross Bowie and Amanda Walsh. Walsh, interestingly, was going to play a character similar to Penny, but we will have more on that in a moment.

If you think that a casting switch would have made a major difference on the show, then you will be really surprised to learn about some of the other creative decisions that could have drastically altered the show's success.

The Original Roommate Scenario

Back before the show that fans came to love was brought to life, Chuck Lorre was still sorting out the final details and getting things to a palatable place for audiences. During this time, Lorre actually had different plans for the pilot, including a complete lack of Penny, who became a classic character.

According to , "The original pilot didn’t include Penny at all. Sure, there was a female character, but she was a far cry from Penny. A character named Katie was supposed to serve as Penny, but her darker nature and propensity to take advantage of both Sheldon and Leonard didn’t sit well with networks."

It's hard to even imagine what this show would have looked like without Penny on board, but it is especially weird to imagine a darker character taking her place.

also noted that, "The original plan was to have Katie live with Sheldon and Leonard after she is dumped by her married boyfriend. The duo, who in the original pilot, were both motivated by sexual attraction, were supposed to invite Katie to live with them in a spare bedroom."

Gilda, a character from the original pilot, was also written out. This character, however, wears essentially laying the groundwork for Amy too come along much later down the line.

nearly looked a whole lot different, but thankfully, Chuck Lorre found a winning formula and crafted a hit series.