I was originially looking for a car in the 50-60k price point and when I came upon the Tesla Model S I was sold for the exact reasons that rcc stated. I felt the compromises that I had to make to own a Merc E class or BMW 5 series were greater then the compromises for the Model S. I wanted comfort, performance, room, and practicality as my primary considering factors. With the E and 5 the compromise was price. To get the performance of the standard Model S in the BMW or Merc I had to get an AMG or M series but then gas mileage went out the window (plus I would have yet another car that required premium fuel) which ultimately raises the overall cost of the car. From a practicality standpoint, I had to pay a significant price premium to get into those cars with no additional benefit. I just couldn't justify the BMW and Merc price for what I was getting (which most of the features are available in a loaded Camary/Accord). Compare this to the Model S which gives me cool technology that you can't find on any other car plus the Supercharging.
Ultimately, the Model S made for an easy proposition to pay above my original price-point to essentially make no compromises. Cool tech, no gas, space, luxury, and performance. This was all before I actually drove one! Once I had an oppotunity to drive one it was a serious no-brainer for me.
FWIW - I have tried HARD to find another car that excites me as much as the model S and I just can't find one.