So I actually might be something of an expert when it comes to blowing myself up in strange and unusual ways - in fact, I made a video series about all the various different ways you can trigger that insurance rebuy and compiled it for "101 ways to DIE in Elite Dangerous":
I can say without a doubt that the most HORRIFIC way to die is running out of oxygen on foot. The most FUN way to die is in the caustic explosion of a Thargoid you just bonked to death. And the most BEAUTIFUL way to die might be a coin-toss between losing control in the cone of a Neutron Star or getting yeeted by a geyser into the stratosphere.
In terms of the "DUMBEST" way to die... I know it's entirely subjective, but I would say engineering and stripping down a Viper Mk3 for maximum speed, equipping it with dumbfire missiles and then boosting into your own ordinance after firing made me actually feel my IQ dropping down to my toes. So, that's got my vote.