Its Science. It's Entertainment. It's family-friendly. It's educational for the children.
It teaches the scientific method, critical thinking, and a thirst for knowledge for knowledge's sake.
This is one of the few shows that can keep me paying the exhorbitant cost of cable. And a great argument for new rules requiring an al la carte option for cable. If I paid for basic cable ($19.99) and then had to pay as much as $3.00 per additional channel for the ones I wanted, I could come up about $15 bucks a month less than I have to pay now.
We figure we need about 12 channels. We looked at satellite, but in the one case our 12 channels are scattered across three of their plans (which together are still cheaper than cable).
I use Verison DSL for my internet, I'd love to get rid of my cable. I only got cable for the 2000 olympics, but I am too weak to rid us of the evil. And Mythbusters is one big reason.
I'm watching electric sparks jump to a kite as I write this (which fits in with the Caption Contest over at Bacon's Rebellion -- Go submit your entries now, reader(s)).
I still like the show even though the one tech guy said "we just killed a dead president". Fortunately my children laughed, and the others said "He wasn't president". The learning never stops.