If I was going strictly off financial rationality, I would probably be best off with a 10-year-old Camry or Prius. Although I'm not quite as fanatical as some on here, my motivations are a combination of philosophical, economic and image. I do consider myself to be somewhat of an "early adopter" type, but not bleeding-edge, most of the time. I also want to hasten the United States' independence from oil, decrease OPEC's influence on geopolitics, and by extension, weaken ISIS, Al Qaeda and other nefarious organizations funded by petro-dollars. I know it's not an overnight process, but the quicker we can get there, the better, IMHO.
I also want something cool, fast, and rare (at least initially) that fits my needs. I actually hope that the Model 3 ultimately becomes as commonplace as the Prius, Camry and/or 3-Series, but selfishly, I kind of want the satisfaction of knowing I was one of the early adopters.