(Can't...stop...the... voices....)
<RANT-MODE ON>
We have a graphics designer here who shouted loudly and constantly that she absolutely had to have a Mac to do her job. She was working with Photoshop, had one of the best machines in the company, but it wouldn't do. When asked what a Mac would give her that her current PC wouldn't, she kept falling back on stuff like "you can click this key and that key to do this...", "the monitor's better" or "a Mac's just better".
We showed her the equivalent hotkeys in Windows, bought her a new, decent monitor (because that's actually a reasonable request for a graphics designer) and then showed her the specs for her current machine compared to the £2k+ machine she was proposing. Then we started giving a list of reasons why we wouldn't be buying one (mostly surrounding the fact that it wasn't cost-effective to spend the time figuring out how to attach it to the Windows domain, train support staff on how to support it, or spend a daft amount of money on a machine that's worse than her current one in every measurable way). IT helpdesk said no. She raised it to the engineers. They said no. She then raised it to her boss (head of Marketing, who bought it completely), who raised it to the IT director. Who laughed, then said no.
Then they raised it to the MD. So often, in fact, that he ended up storming in to the IT director's office and told him to get the damn thing because he's fed up hearing about it, and that the head of Marketing / graphics designer had better produce the increased workflow promised.
She got her Mac. We had to hire in a technician to hook it in to the domain & network (and it fell off again within days). Her performance actually went down. But on the plus side, all the technical issues she kept throwing our way (along with comments like "this wouldn't happen with a Mac") suddenly disappeared because she refused to admit that her beloved piece of Apple-ware had any problems.
<RANT OFF>
Whew, that feels better. Sorry, that word is one of my triggers.