Just found this thread and want to add my thoughts.
I collect posters first and foremost because I am a film addict. Always have been, always will. Film is my life and have amassed a huge DVD/Bluray collection too (is this considered 'a male past-time' too???)
Secondly, I studied graphic design and art history so the two fuses very well.
It's true that I only seem to collect what you guys may consider more 'feminine' - french nouvelle vague, artwork over photos etc... but that's not always the case as I also have Brazil and Blade Runner because they are my favourite films.
I started out just collecting loads of cheap posters, like most of you did, but I've now become very selective and have decided to only buy one or two 'good' posters a year because I just don't want to own loads of posters. Maybe that's the difference. Women are more selective? But it's true, I do get weird reactions when I tell people i collect film posters but more due the fact that they cost a lot rather than being a woman.
My boyfriend likes my passion for posters but he doesn't understand why I collect them (though Brazil is his favourite film so loves my Quad and wants that hung as soon as i move in!) however he doesn't want many to be framed so my collecting has to be limited now.