I owned a 2003 and the 2007 has a little more giddy-up and better audio. My opinion hasen't changed since 2003. You won't find a better "fun car" at under $35G. This car will handle itself rather well against any car I've come across except for the Corvette. However, in a series of S turns the Vet couldn't keep up. It's insane how the S2000 handles all styles of cornering. I know the tires have a lot to do with it but still.
Handling and engine sound. Also, the feel I get when driving down the road. You can't help but feel special.
Still needs more torque. If they threw in 50 more pounds of torque, I wouldn't have to worry about looking foolish when a Vet pulls up next to me revving its engine.