Van De Graaff generators are easy ways to generate high voltages with practically no current. If you have the financial means you can easily generate one million or more volts with a VDG generator. It's basically static electricity generated from friction that is transported to a large metal sphere where it is stored.
Be aware that electrostatic generators, like Van De Graaff, are able to hold very high voltage without breakdown thanks to their shape: smooth and round. Breakdown is inversely proportional to the local radius of curvature of the conductor (assuming we are dealing with bare conductor in air).
If you attach a wire your Van De Graaff sphere, you will drain off most of the charge.
If you turn off the lights, you will be able to observe the corona discharge occurring at the tip of the wire.