What geophysical instruments should I use to detect water without drilling? How can one detect (preferably artesian) aquifers nowadays that a lot of sensors are available? Should I use ground-penetrating radars, neutron detectors, or any other advanced devices? Can seismic imaging be used to characterize the extent of the aquifers?
Hydrosource Associates (no personal relation) claims to use the following:


  HSA’s use of geophysical instruments and methods includes seismic, electrical resistivity, ground penetrating radar, electromagnetic, magnetic, gravimetric, self-potential, and magnetotelluric.


Since you're looking for a list, you could investigate each of those technologies above.

However, the one instrument not mentioned above and the most high recommended method is simply using geological maps.