SS-18 ICBM
Oscillator
I'd probably go with an autoclave. Caked-on residues don't stand a chance against 121°C steam at 25 atmospheres of pressure. And it seems it might be useful for canning too.
A shaker table so I could rent it out to every single university satellite team in the region. XD
Hydroponics. So many uses...
At home? I suppose if you have the space and power, why not.
Grow-op?
Though I am curious which edible plants can't be grown with a typical garden.
There's remarkably little equipment needed for genotyping; an electrophoresis gel stand and a pcr machine...
Ethanol still. Distil absolute ethanol from magnesium ethoxide and mix it with rainwater.