Once upon a time, I was really into such free trends / personality test and would always share them here when I got wind of it. Lucky you cos that old me is back and the latest personality trend which is pretty fun is this by Design Expo. I even saw people playing it on the train.
There is both an English and Mandarin version (content is similar), but given how "great" most of our Mandarin are (and it is in 繁体字 by the way), I would suggest doing the English version (link here) for a more enjoyable experience.
Generally, the personality test ask a series of questions (story form but somewhat ridiculous storyline) and you pick 1 out of 2 available options. It shouldn't take more than 15 minutes to complete. The fun part is the aftermath where you send this to all your friends to find out how compatible you have been, hahaha. I would say there is some accuracy since most of my friends are of a certain pattern with extremely strong personalities.
Initially, I thought this was the usual half-ass personality test with 8 options at most. But apparently, there are eons of combinations. I did twice but still got the same results. I don't think it is because I am consistent but more that the questions were phrased in a way that would always derive the same response for me. Haha. Do try it out and have fun!