If we have interacted, you would know my response already...
To me, this is NOT the most important question you should be asking. Before you call any agile consultant, Kanban specialist or a RUP expert (?!$!), I would recommend you find answers to the following questions
1. What are my business objectives?
2. Does my current software development methodology encourage behavior aligned to my business objectives?
3. If not, can it (existing software development methodology) be optimized to align with my business objectives?
4. If yes, Which practices from other software development methodologies can integrated with my existing methodology?
If not, (Must you change to a new software development methodology)
- Which behavioral changes you would like to see in your work force?
- Which software development methodologies encourage such behavior?