If I'm interested in getting an answer that is minimally correct what is the minimum basis set level I should use? (i.e. anything less would be much less reliable)
Obviously this depends on the methods, property of interest and opinion.
Let's say I'm just interested in relative energies (but feel free to chime in with information about properties if you are inclined). I am interested to hear how this depends on the different methods and the various arguments there are for minimum basis sets one should use.