Originally Posted by pixellany
I agree (logging out normally)
When my system locks up, I try ctrl-alt-EVERYTHING before simply pressing the reset button.
Failing that, if you have the relevant option turned on in the kernel, you can still use some key combos to do a somewhat safer shutdown
Lalt+sysrq+u will force an umount on all the mounted volumes, this is the most important one, because it prevents disk corruption and fsck when booting the next time. After that you can use the reset button or even use Lalt+sysrq+b to reboot the system.
However, as said, this only works if you system has the relevant option enabled and it didn't crash in a really hard way. If the kernel died completely then there's no magic combo that will help.