  Energy-momentum is an important conserved quantity whose definition has been
a focus of many investigations in general relativity. Unfortunately, there is
still no generally accepted definition of energy and momentum in general
relativity. Attempts aimed at finding a quantity for describing distribution of
energy-momentum due to matter, non-gravitational and gravitational fields
resulted in various energy-momentum complexes whose physical meaning have been
questioned. The problems associated with energy-momentum complexes resulted in
some researchers even abandoning the concept of energy-momentum localization in
favour of the alternative concept of quasi-localization. However, quasi-local
masses have their inadequacies, while the remarkable work of Virbhadra and some
others, and recent results of Cooperstock and Chang {\it et al.} have revived
an interest in various energy-momentum complexes. Hence in this work we use
energy-momentum complexes to obtain the energy distributions in various
space-times.
  We elaborate on the problem of energy localization in general relativity and
use energy-momentum prescriptions of Einstein, Landau and Lifshitz, Papapetrou,
Weinberg, and M{\o}ller to investigate energy distributions in various
space-times. It is shown that several of these energy-momentum complexes give
the same and acceptable results for a given space-time. This shows the
importance of these energy-momentum complexes. Our results agree with
Virbhadra's conclusion that the Einstein's energy-momentum complex is still the
best tool for obtaining energy distribution in a given space-time. The
Cooperstock hypothesis for energy localization in GR is also supported.
