There are many personality assessments out there, but Tilt365 is my favorite. Not only is it spot on, but the philosophy is to be mindful of both your strengths and weaknesses so you can improve on what doesn't come naturally. More so, when you understand the Tilt dynamics of the people you work with, you can better understand why they communicate the way they do. It's a fascinating exploration that always generates insightful reflection and positive impact for a team. And if you're willing to really buy-in, you can seek those that are your compliment (or opposite) to work through situations that could otherwise be sticky.
The scientific strengths assessment Tilt365 identifies my personality as Structure: The Master Mind. Click the link to see if the description maps to how I describe myself.