Most are made up and silly.
The only one I've liked was in college I did a "communication style" one. Where it showed a bunch of different like emails, posts, and conversations and asked which you preferred to receive and which you were likely to write.
10 years later I still think about it, cause the goal of the work was to talk about how if you're a certain communication style what to keep in mind with communicating with others. Like tips to not get frustrated with yellows who don't care about facts when sending emails and how to write emails that don't bore and frustrate people if you're blue. (I'm blue green. I can sometimes write long emails)
I thought about it the other day cause a guy was complaining about all these emails that didn't seem to say anything, they were just about feeling good, and he just wanted them to spit it out. Which corresponded to firey red getting mad at green.
So with that context, do you have any that actually had an impact on you?
Most personality tests will not tell you anything about yourself that you didn't already know, it will not give you any insights into the correct way to live your life or what is going to work for you.
However, it can help you frame things about yourself in a new light or to help you come to understand the way that you work inside of a larger social picture.
So they don't work to tell you who you are, but they help you be who you can be.