realistic lighting overhaul has really really dark nights when compared to climates of tamriel. I haven't tried any others. Also, climates of tamriel is more immersive (it feels more nordic), but realistic lighting overhaul looks less realistic and more vibrant colors.
I use those. Best lighting mod. RLO is the worst (disgusting orange light at every single turn, touts that it's "realistic" but took Pluto's amazing work and ruined it, proceeds to then garners donations with the brand name).
ELFX is definitely amazing in it's own regard. However, there are certain changes which I don't enjoy such as http://static.skyrim.nexusmods.com/mods/images/27043-2-1353219433.jpg because it changes the feeling of these places too much (not enough light). Where as Relighting Skyrim is more like this http://static.skyrim.nexusmods.com/mods/images/17609-1-1345091982.png