Metal-benzene complexes provide classic examples of organometallic chemistry, and their ions have similar appeal for mass spectrometry and ion chemistry. This review covers new formation methods for the generation of novel metal ion-benzene complexes and clusters in the gas phase, as well as new measurements of their properties. Collision induced dissociation, radiative decay kinetics and photodissociation methods have been applied to determine bonding energetics, while UV-vis, infrared and photoelectron spectroscopic measurements have been applied to determine structure and bonding patterns. Electronic structure calculations have been pursued to complement these various experiments. This review surveys recent progress in these areas, providing an overview of the field and suggesting future research directions.