Get ready then - I personally own 10, with DH owning another 10 (or maybe 11). I like Zen's philosophy, but a couple more and I have two Tuesday bikes that can't possibly be ridden on Wednesday. I was recently asked what my favorite bike was, and my reply was that it was whichever one I was riding at the time.
And there is no permission on either side at our house - they just show up (although we are STARTING to institute the one in one out rule...).
Many of you have seen this from me before, but the optimal number of bikes is n+1.
SheFly