There are lots of very good quality window films.
If you want just a smoked/black tint, look for a metal+dye hybrid that has a manufacturers lifetime warranty against fading, discoloring, peeling, cracking, bubbling, etc etc etc. However, there are fully-dyed (no metal) films that now carry such a warranty, like 3M's Color Stable line.
If you want a slight reflective/mirrored look and you don't have any internally mounted or glass embedded radio, GPS, or satellite radio antennas, go for a
full metal film, in which just about all of them carry the lifetime warranty.
List of fully metalized films:
3M - Black Chrome
SunGard - Endurance or Endurance EX
Llumar - Platinum Plus
Solar Gard - HP Quantum
SunTek - InfinityOP
There are others, but those are the only brands I've seen or had experience with.