Sean, I don't think you can ever own enough chainsaws. I don't know how many I have right now, but I'm comfortable in saying it's up over 10.
As far as ones I use regularly, probably three? I have an old 038 Magnum with a 25" that I did a little work on years ago, and I get it out now and then just cause I like to hear that thumpity-thumpity idle that they produced. Just flat cool.