For as stereotypical of a character as Penny was supposed to be, she definitely was very likable.
Before I ever seriously watched the show, I do know why Kaley Cuoco was casted as Penny. Her character was supposed to be the hot blonde girl that all the nerdy guys fawned over and that was mostly true unless you count Sheldon.
But what made her character more real is the fact that she was a working class girl trying to pay her way, though she was often out of money. Always found it funny that when she worked at the Cheesecake Factory, that it looked nothing like the Cheesecake Factory in real life.
While you do root for Penny and Leonard to eventually get together and marry (which happens) their marriage is actually pretty terrible. Leonard is for the most part a whiny cheater and she’s actually a pretty decent wife. I was actually rooting for her to leave his butt.
I think my favorite thing about Penny was her being a second mom to Sheldon despite being younger than him. It just worked.
I can’t remember if she stays in that position at the end of the series or not but she does have a professional job working for some pharmaceutical company. And she’s moderately successful at it too. I definitely respected her for that.
While she isn’t my type, I do have a different kind of fondness for Penny than most male viewers of Big Bang Theory. At the end of the series they confirm that she’s pregnant with Leonard’s child. I would actually like to see a reunion special where they show this new kid.