Your requirements for a tool is what should be driving our decision, what may be a problem to me may be a requirement fulfilled to you.
1. Define your requirements of a tool.
2. Evaluate which if any of the tools you mention fit the requirements.
3. Do a Proof of Concept for each tool to prove that they fit the requirements.
4. Select the one that is best for you
Note that Test Director has more functionality than bug tracking - you can also track you test cases with it. So you might pay for a part you don't need.
But as Lynne says, maybe the bug tracking part of Test Director is what fits best you requirements. Do follow the steps that Lynne suggests. In fact use this for any tool you need to select.