Let there be light... but not too much of it. Ok... so you HAVE TO keep something in mind. MOST of the time your fish could CARE LESS about what kind of light they have up on top. Sure if it's too bright they might hide under your plants or not be able to see too well after awhile.
Generally fish need very little light and many times the little bit of light naturally occuring through the windows might even be enough for some species. Certainly in many cases the standard light fixtures are all that many fish care for. So now that we have this information covered let's move on to who the light is really for. Pick one: A) You. B) Plants/Coral. or C) Both.