My favorite car can't really be described since each has it's purpose but MY NTC3 will always be my favorite since that's what I got into the hobby with. It is a great basher. It's well balanced, when set up correctly. The drive shaft makes it less prone to pebble and breakage like the belt cars. The NTC3 is also a very capable racer. It takes new setups very well and also allows the driver to grow with it without overwhelming the new driver.
I took my NTC3 racing this season and learned so much from it. It allowed me to learn how to prepare it for the race but most of all it was very forgiving when mistakes were made. It taught me to be smooth in my driving as well as throttle control, which is key in handeling characteristics. As I said, it teaches the driver the dynamics of running nitro and encourages you to improve instead of frustrating the driver when things don't go as planned. This car is easy on the novice driver and great for the intermediate but it also has it's limitations, agility and performance wise. That's why I moved on to the Serpent710.
The 710 is definitely NOT a "parking lot basher." This car demands to be raced and quite frankly, I beleive the track is the only real place where the abilities of this car can be truely appreciated. As a racer, this is my favorite car. Agility, suspension tuning, overall design ... this is my favorite car for the track.
Don't get me wrong, the Mugen MTX-3 is also a great car. Also well suited for the track and has the same demands as the 710 ... to be raced, not bashed. Other cars out there such as the Kyosho VoneRR and RRR are wonderful racers as well. Ratzo has the VoneRR. Good performer, but I have never driven one so I can't give an overall review on it.
My Picks for a parkinglot basher and/or beginner to intermediate competative racer is the Assoc. NTC3 and for competative organized racing, the Serpent710. But I don't disqualify the Mugen MTX-3 or Kyosho line either.