I'm a man of science, and because of this I evaluate this question in a certain way; logically and based off of available data. Nuclear energy is in my opinion the best practical option for alternative energy to fossil fuel based electricity generation. The reasons for my support are summed in three simple advantages: it is a highly concentrated source of energy that can be easily controlled, in terms of spreading pollution that is inevitable from any practical energy source; nuclear is next to zero atmospheric or aquatic pollution, and finally nuclear is well regulated in the United States and it's absolute worst case disaster resulted in no one receiving anything even resembling an extraordinary amount of radiation.
Nuclear is a highly concentrated source of energy as compared to solar or wind based power sources. This means that in terms of physical infrastructure; far less must be built to generate our power needs with a highly concentrated source. Also an aspect of it's concentration of energy is that nuclear power is controllable and not subject to forces beyond our control. This is a highly desirable trait for a world where power demand is not uniform during every time and where to date we have no large scale ability to store electrical energy. Lastly as a side note: Uranium and especially Thorium are easily available in the continental United States and the supply of Uranium would take a minimum of a century to use up (if you don't include using disarmed nuclear weapons) and Thorium is for all practical purposes unlimited.
Nuclear fission results in no atmospheric pollutants other than water vapor if you consider it a greenhouse gas. It also does not irradiate water or dump highly toxic radioactive waste into rivers like some people fear. It simply stores radioactive waste in sealed concrete containers designed to prevent the waste from ever even having a statistical chance of escaping let alone a practical one. Also it should be understood exactly what nuclear pollution compares to something like say coal. Nuclear power puts a couple barrels of highly radioactive waste in perfectly safe containers in a high security facility in the middle of nowhere where it only pollutes the inside of the barrel whereas coal pollutes the air with greenhouse gases, pollutants dumped into water systems, and displaces top soil which is basically irreplaceable. So then what about solar or wind, what kind of pollution do they produce? Well not only do they use more than a handful of poisonous metal substances in their construction, but they also use up significant amounts of valuable rare elements like alkaline earth metals and other rare metals.
As for the safety of nuclear energy; there has only been one major accident in United States history and it resulted in irradiating the interior of one building with no casualties. Also frankly there are around 20 things that have to be messed up for a total nuclear meltdown and they are basically impossible.