I'm writing a research paper on Hades, king of the underworld, and I really wanted to know if Hades was really a bad guy.
I have many pages of evidence saying that he isn't. But I would like to know your guys' opinion.
Hades main story involved the abduction of his niece, the Kore (aka Persephone), and subsequent forced marriage. So, from a modern perspective, we could say he is a bad guy. But, it's important to remember that incest among the gods is not a crime--Zeus married his own sister! Forced marriage was also the norm, certainly for nobles, until fairly recently. Hades shared his throne with Persephone, and, through the Eleusinian Mysteries, she becomes a goddess most esteemed.
Hades is often regarded as the "anti-Zeus" [see Diis/Dis Pater] --Zeus' realm is the sky which is filled with light; Hades realm is eternal darkness. So it would be easy to see Hades as "evil", except that Zeus is not strictly "good". (The pagan "Sky Father" is as susceptible to human foibles as anyone, despite his cleverness--Hector has far more dignity than Zeus!)
As Hades transforms into the Roman variant, he is much more associated with the wealth of the subterranean regions--Pluto ("wealth", from the Greek πλοῦτος). In the Orphic Tradition, Eubuleus ("wise in counselor") is associated with both Hades and Zeus. Heraclitus even suggested that Hades and Dionysus are the same god, representing the life/death dichotomy in the context of eternal renewal.
Theoi has a nice compendium of Hades references. My sense is that Hades mostly chilled and did his thing. In terms of bad behavior, Zeus is sort of the poster boy for that, and Hades is, by comparison, pretty well behaved and low-key.