I don't know why I didn't recommend it before, but Kikaider: The Animated Series. Unfortunately, the 20 something episode series costs $50-60. But I'm still getting it because I love that series to death. It's extremely dark, gritty, and balances out a great plot and loads of great fight scenes.

Full Metal Alchemist: This is probably the best anime in existence. It equals out comedy, romance, action, adventure, story and molds them all into 1 perfect show. There has never, ever been a show that has made me think more than FMA.