I love crazy crossovers. I've dreamed up a few every now and then and mentioned them to my sister (she tends to be the person I bounce ideas off of most). Usually she laughs and wants to know how the heck I'll make them work, but occasionally I get her excited approval and dares to write it. I think I've only posted one of them come to think of it, because, well, they're crazy crossovers. :)

I still save the ideas I don't write as challenges on my hard drive because it amuses me to look at them.

You should definitely write more of that Gilmore Girls/Atlantis crossover. That's not just a crazy idea, it's absolutely brilliant.