Over here in dalekboy's LJ the comments have drifted to mentioning the BOFH: the Bastard Operator From Hell.
Like tikiwanderer, its been a while since I've read any of the BOFH but I have, on occasion, been known to refer to myself as the Bastard Business Analyst From Hell. :)
All jokes aside, I actually try for a much more collaborative approach with designers/architects/developers. The goal is to get a system that is good enough to do the job, accepted by the business, and well enough designed to support maintenance and enhancements. A confrontational approach just doesn't deliver that. Its my role to identify, clarify, document the business requirements, and make sure that they are achievable within the system: to do that I need to at least understand the headspace that the design/development team are in so that I know the constraints.
But sometimes I get caught between the mineral deposit of an absolute non-negotiable requirement and the unyielding location of technical difficulties. And thats where the jokes come from, sometimes if I don't laugh I'm sure as hell gonna want to cry. :)