Hi there -- FYI, I own a Zanardi edition.
1) What is the thing that bugs you the most? a rattle, a little this, a bit that?
Wow, definitely a car that's hard to criticize, but here goes:
1. Needs more horsepower and torque. The car is getting old, and the NSX is falling behind.
2. Stock, the handling isn't so great -- too much body roll. If you're a serious sports car driver and unless you're buying a Zanardi (or are in Japan and buying a Type S or S-Zero), you'll want to do something with the suspension.
3. What is it with the Japanese and their propensity to put tiny tires on their sports cars? The NSX simply needs more rubber on the pavement for better handling.
2) What is the thing you love the best? Acceleration, Stereo, Handling, the short shifter, the engine hum?
Heh, there's not much to not love. Perhaps what I love most is the overall feel... as a complete package, all things considered (handling, performance, build quality, comfort, road-ability, track-ability, reliability, appearance, etc.), it's the best (although once I put a bunch of time on a Porsche 911 TT soon, I may change my mind -- we'll see).
There are faster cars, there are better handling cars, there are better cars for the road specifically, and better cars for the track specifically... (although there probably aren't better built cars)... but overall, when everything is considered and averaged together, it's probably still the best all around sports car.
Summary: do you want a car that's a 'specialist' or a 'generalist'... if the latter, go with the NSX.
-Z18