It seems like the character of Tantalus changes pretty drastically depending on which version of his story you read. Depending on which kind of crime he commits, he definitely becomes a different kind of dude. In one version, he hides a golden dog for a guy named Pandereus, who stole it from a temple of Zeus. When Hermes shows up to question him about it, Tantalus totally lies about the whole thing. Okay, so this makes Tantalus a liar and a participant in the apparently thriving golden dog black market, but it's definitely not the worst crime that Tantalus is accused of by other writers.
We're going to go out on a limb and say that most people would think that Tantalus's whole foray into fine dining is his worst possible crime. In some versions, Tantalus chops up his son Pelops, boils him in a pot, and tries to serve to the gods at a dinner party. (Every time we write that it seems like it's more messed up.) Tantalus says he does this to test just how all-knowing the gods really are. Are we crazy, or are there a lot other ways one can test the gods, which don't include dismembering and cooking your son? In this telling of the tale, Tantalus seems to come off as sadistic and downright deranged.
In other versions of the story, Tantalus is punished for sharing the divine secrets, told to him by his father Zeus, with other mortals. Tantalus is far from the only mythological figure punished for this sort of thing. Probably the most famous is Prometheus, who was punished horribly by Zeus for giving man the secret of fire. Interestingly, Prometheus tends to be viewed as a hero for giving man valuable knowledge, despite the fact that he defied the gods. Tantalus, on the other hand, is almost always thought of as one bad mamma jamma. Could it be that the darker versions of the story have totally tainted the T-man's reputation?
Pelops is a lucky guy. Okay, maybe he isn't so lucky when his dad, Tantalus, decides to dismember him and serve him as dinner to the gods. However, he is pretty lucky when Zeus decides to put back together again, Humpty-Dumpty style. In the end, Pelops makes it out of the awful situation with everything but his shoulder, which the distracted Demeter accidentally eats. Even this is made right, however, because Zeus gets Hephaestus to carve Pelops an awesome new shoulder out of ivory. We're guessing a god-made shoulder is way better than the one he had before anyway. Pelops later goes on to be a powerful king in his own right, and he famously fathers the dueling brothers, Atreus and Thyestes.
In a whole bunch of myths, Zeus is the one up to no good. Like the many corrupt politicians to follow, Zeus spends about half of his time seducing innocent young maidens and the other half trying unsuccessfully to hide his affairs from his fuming wife Hera. In the tale of Tantalus, however, Zeus actually comes out as the good guy.
When Tantalus commits his horrible crime, Zeus acts as a force of justice. Not only does he punish Tantalus, but he also rights the wrongs committed by putting Pelops back together again. Quite often, Zeus was worshipped as a force of justice in the universe, as the guy who made sure that everything was fair and right. In this myth, we can totally see why.