My 3 fun cars illustrate this very nicely. The 135i is far and away the fastest and most capable but is trying to kill me all the time - its like a fight, you feel compelled to drive as fast as you can in it to get the most rewarding experience. When it goes wrong it will be massive
The 355 is still a very fast car but its more like ballroom dancing, it works with you, covers up your mistakes and although its more fun as you going quicker its still awesome at 60%.
The MR2 is impossible to drive without grinning, it has all of the BMW's "make me go faster" DNA but isnt powerful enough to get into major trouble or expensive enough to worry about the inevitable armco/ditch/hedge interface.
Ive got a trackday coming up (hopefully) and Im genuinely torn which car to take, its a good problem to have.