As a member of APA, I administered a number of personality tests to 100s of people for several years and have taken those tests AND a range of "pop psychology" tests for my own information with these results:
1) The most useful personality tests to me have been the MMPI (the long Minnesota Multiphasic Personality Inventory), the IPAT=16 (16 personality factor test), and the House-Tree-Person test. Others are the Work Values and Work Motivation Tests, which I found accurate most of the time. The Myers-Briggs does not work well for me personally, but it works accurately on about half the people to which I administer it.
2) The pop psych tests involving flowers, colors, one-word, and many others are inaccurate for myself, but surprisingly, they work pretty well for about 1/4 to 1/3 of other people among my contacts and clients that I know have used them.
My advice is to take more than one personality test - at least 3 different ones of any sort, and see if you notice a consensus. (Even a single MMPI can be incorrect.)