That kind of crash is called a kernel panic. The log of the kernel panic is saved in NVRAM at the time of the panic (if possible), and written out to a file in /Library/Logs/PanicReporter/
at the next boot. If you post the contents of your panic log, people can possibly glean details of exactly what part of your kernel is panicking.
If you're super lucky, it could turn out to be some crappy third-party driver for a piece of external hardware you don't really use anymore, and you can just move that driver out of your /System/Library/Extensions
folder and be done.
You can opt to have the panic log text displayed on your screen instead of that multi-language graphic by entering the following command (the panic log will still get logged to disk as well):
sudo nvram boot-args='debug=0x100'