If your primary goal is to have a fun car to drive, nothing on the list compares to the Elise. I just picked one up, and I can say that it is without a doubt the most fun, lively, smile-inducing car I've ever driven... and I've driven a few.
It's not the most comfortable car in the world (especially with the sport package, it jounces and bounces over bumps in a way that's very similar to a kart). When you're at freeway speeds (or getting on it), you really can't hear the (crappy to start with) stereo at all. You will frequently make a fool of yourself trying to get in/out in front of the people who stop to gawk at the car. The truck won't fit a case of wine and the (rolled up) soft top at the same time. It's hard to park and walk into a store without getting into several conversations. Being next to an SUV on the freeway is scary, especailly when they veer into your lane while looking at the Elise rather than the road.
But it is uncompromisingly FUN. Quick enough to be entertaining, and corners... don't get me started on corners. Highly, highly recommended.
My new toy (the red one, not the yellow one
):
Cheers
-b