You can play with different film colors with higher heat reflectivity... but by doing that i feel it can look tacky. Neutral black is the best looking and still provides a purpose.
My parents and I have used Snaptint.com for all of our vehicles and its quality film.
Neutral black - 35% on the two front windows, 20% rear windows. 35% is just light enough to keep the police off your back, and just dark enough to provide you with a little privacy and sun protection. And obviously, keeping 99% of UV rays off the interior.