Which mixer to buy...

[I apologize that I have not posted very frequently recently. I've lived in 3 different places in the last 2 months as I slowly make my move to Champaign, IL. So if you made it here from FoodieBlogroll, never fear! When I get settled into my new kitchen, I will be posting away. So follow me, bookmark me, whatever... Stay tuned!]

I need some input... I've decided that my cooking just cant continue to advance without adding a stand mixer to my kitchen :) So I was wondering... Does anyone have input on which Kitchenaid to get? The Pro Line Series? The Professional Series? The Artisan Series? I know I want one who's head tilts back, and I can tell that the Artisan has this feature, but I cannot tell for the others.

Any advice?