As far as those states go....they're pretty similar. At least grouping those 3 when comparing to something like New York, Florida, Minnesota, Washington, etc. This is climate, topography, politics, etc

Missouri has probably the most "diverse" landscape if nature is your thing. Ozarks with lakes and forests and hills. Fun rivers to canoe and kayak and fish. 

Nebraska and Kansas to me are "drier" states and landscapes. More prairie, more irrigation needed in farm fields where they can, more livestock feed yards. Of course the sandhills of NE are unique and other spots too. If you want trees, forest, water...I'd vote for MO over the other two. Of course you may not really be able to choose but hopefully you can!