Single plane tilt sensors work great for digital sensing, but I really like the ADXL 3 axis accelerometers.
The ADXL335 puts out an analog value proportional to angle on each axis, so is easy to interface to an arduino if you have the analog pins.
Arduino tutorial: https://www.arduino.cc/en/Tutorial/ADXL3xx
Now you can set triggers ranges anywhere. I used an earlier version of this on a car lot alarm system I designed, and it allowed for parking on a hill, adjusting settings remotely to compensate for strong winds, etc.