The most egregious fanboys of the world by far are Microsoft fanboys. They span the globe and make the universal "oh, brother" sign whenever someone would dare suggest another platform. It does not matter which. It could be OS X, a flavor of Linux, Solaris, you name it. Whichever you mention, YOU are labeled a fanboy of that platform. It confuses them if you mention more than one, because then they're unsure how to categorize you. If they work for IT, if you say Microsoft they are rearing to go but if you dare suggest another platform they need test results, benchmarks, etc. and are looking for any single excuse to be against the idea, even if ABC other platform is proven to perform XYZ much more safely & reliably at a lower cost, and if you tell them that you can be sure they're calling you a fanboy of ABC behind your back, which ironically makes them, and/or the people they are beholden to, the fanboys.
Spot on comment. I see this everyday. You really do get marginalized if you mention anything other than Microsoft. I even had one guy cut me off one day.
Me: so, on my Apple compu....
Him: Dude, you've got to cut out the Mac business, its not going to get you anywhere.