yeah right... Only Space Runaway Ideon is deserving of that title Greatest anime ever. I prefer shorter well constructed and well choreographed battle scenes, rather than longwinded repetetive overused battle scenes. I also fail to see your logic, you say that mystical demigods from space are more realistic than feasible humanoid machinery? How can you say that when both Neogentronyx and a Japanese company have already built and personal mecha units? In fact, Neogentronyx sold its first working prototype on ebay for $40,000 several months ago.
Just because the DBZ Characters are aliens doesn't make it any more feasible, Mecha are already being developed and made, while there is still no evidence of intelligent life on other planets. Therefore, mecha is more realistic. Whether you want to admit it or not, mecha is still more feasible and than Dragonball Z, because saying that Dragonball Z is realistic is hovering very close to illogical fanboyism. Realism has nothing to do with how much you enjoy a show, and poor character designs also have nothing to do with realism.
If you are talking about raw power, Ideon beats out DBZ by a long shot, Ideon freaking wipes out the entire universe, killing just about every living thing among all the trillions of planets.
(general laugh)