its not which is better its which do you like
c'tan nightbringer - a brick shithouse in close
c'tan deciever - slightly (and i mean slightly) less powerful than nightbringer, but he allows you to do alot more annoying and tactical tricks
necron lord - a cheap, good model. frees up the most points from your list, but also he gets a res orb which niether god has access to.
keep in mind the gods are flying solo, they cant (from what i know) join other squads, which means they could get singled out before they have effectivenes where as the lord can throw wounds at the troops around him and use the res orb to bring them right back up