As an IT Professional, part of what I do when assigned larger projects from management is to meet either formally or informally with the stakeholders, work to establish a scope and a set of requirements and then compare different solutions in an effort to find the "best" one for this particular situation. Part of this means choosing a software or hardware vendor and committing the company to the implementation and that vendor for at least the life of the project.
Occasionally I will come across a co-worker who is an IT Professional in my team or a stakeholder (either a user or someone in another department's management team) that is for lack of a better term a "fanboy" or "fangirl". Every solution that they suggest or advocate is a particular vendor or operating system regardless of how well it fits the project's business needs. It often seems to come from a personal preference that they bring into the business, generally without a complete understanding of the existing solutions and infrastructure.
For example: Person A will advocate Apple laptops because they like and use Apple laptops at home but don't consider the difficulty in integrating them with an existing Microsoft environment.
I generally try to build a rational fact-based argument that is "solution neutral" but in my experience "fanboys" are motivated by their emotional attachment to a particular solution and get defensive when presented with rational arguments. If reason and logic ruled the day the business world would look very different.
How can I work with people that are always committed to one vendor or company? How can I non-confrontationally make sure we end up with the "best" solution instead of a middle manager's new favorite "shiny toy"?
I love how the comments remind me of implementation meetings I have been in.
A stake holder should not be dictating architecture or software.
You underestimate the power of middle-management and the dysfunction of many work places. Ideally yes, the stake holders should just supply requirements but often they meddle in the implementation choice.
You need a person respected by the whole team to make a decision about what to use, and then the whole team must respect that decision. Who would that be in your organization?
This is tough. A lot of the time I am working with different stakeholders from heavily silo-ed workgroups so it is hard to find someone who fits this description. I have a feeling an appeal to authority would be inappropriate in the sense that the VP would wonder why we are bothering her with such "nuts and bolts" problems and why we cannot get it worked out among ourselves. But I see where you are going with this and I think in different work environment I could see a lead business analyst or a technical lead fulfilling this role successfully.
What is your definition of a confrontation?
People arguing from an emotional standpoint often have an emotional reaction when stymied — they either close up and become silent (not useful) or become recalcitrant and defensive (also not useful).