Eureka 7 is generic mecha anime with horrible mecha designs. Avoid it.
SN has something against E7. I never really got what. Ignore him, though, it's an amazing show, a coming of age story that's almost totally character driven, with some beautifully animated mech fights interlaced throughout. The designs are kinda meh, but still better than anything Gundam or Macross managed.
JoJo's Bizarre Adventure isn't exactly obscure, Ojike. Every high end series from Hellsing to Berserk's got it's roots burried in it. It's the original ultra violence/revenge story.
Speaking of which, read and watch Berserk. It's a classic in all regards, the tragedy of the Black Swordsman Guts and his struggles against destiny. It's almost sickingly violent, but that only adds to the sheer wonder the series invokes.
Hellsing is another beautiful piece of animation. Well, the OVAs are, not the actual show. It's the story of the vampire Alucard and Hellsing, the organization he's sworn fealty to. Right now, the establishment is in the middle of fighting off a Nazi invasion of London, with Alucard fighting a crazed zealot, a so called Angel of Death, and unholy abominations en masse. It truly is the best of the mindless violence series around now.
If the violence isn't what you're after, watch either Death Note (which has already been explained, I see), and Monster, the story of a famed Japanese surgeon who's framed for murder in Germany after a child he chooses to save, despite the consequences to his career, turns out to be a genius, with charisma comparable to Hitler's at the height of his power. He also turns out to be a mass murdering Monster, who views Tenma (the surgeon) to be his hero and idol. Tenma eventually comes to think that the only way he can ever really end the boy's madness is a bullet in his head, and becomes more and more desperate every time the boy passes through his fingers. The story goes far deeper than that, but I haven't finished reading it myself, so I can't go into the finer details. Still, it's an amazing show, done by Madhouse (the best animation studio around), and an even better manga, written by the Japanese equivilent to Frank Miller.
Hope that helps =D
~Dorian Gray