What MBTI test out there do you think is the best?
My favorite is still the official Step 2 test. It costs money though. I attached a sample report as well as the portion of the manual from the CPP website.
MBTI Step 2 Report Example.pdf
I think there are several characteristics of a good one:
1. Accurate results
2. Robust profile description
3. Useful content provided in report
I like all three of those in the Step II.
I didn't find Step III to be especially useful.
Here are some links to where you can get the MBTI Step II assessment.
MBTI Test > MBTI Step II Profile | Career Assessment Site
Myers-Briggs Type Indicator (MBTI) - AnnHolm.net