I just bought my first pinball last month. It has been a great success. I bought a Stern POTC. Why, because my entire family liked it. I enjoy it, my wife liked it the most of any, and my 9yr old daughters love it.
I figure starting with a machine that the entire family enjoys really will help set the tone for future endeavors in the pinball hobby.
So find what makes all of you happy (including yourself) and go for it. Having the most popular machine does nothing if you don't actually like it.