The S2000 is a fantastic, fun car. Once you accept its dual personality, you get what it's all about. When just putting around town under 5K rpm it has decent response but it's nothing special. That makes it quite relaxing and easy to 'go with the flow'.
Then going over 6K rpm into the VTEC zone you enter another world - the realm of the race car. The S2000 snarls, then screams to 9000 if you have the balls to go to redline. It's a beautiful thing. 85% of the time I short shift it because there no reason to go mental. The other 15% is pure gorgeous roadgoing fury.
Greatest car I have ever owned, and my first car was a '73 Datsun 240Z. An M3 or Boxster might be as much fun but to get a car that is MORE fun than an S2000 I'm sure you'd have to spend over $100K.