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?
I used to have a job that was really into the Core Value Index. I thought it was pretty awesome because their categories were really simple and there are only 4 so you can really wrap your head around the whole thing at once.
It's not a full personality test, it's more focused on trying to answer the question "How do you want ideas presented to you?" And. "How do you prefer to interpret ideas?" I found myself making meanful changes in how I worked with coworkers where I knew their results, which isn't something anyone can manage with more complicated tests.