Cyborg 009 is one of the lesser-known anime. It just came out of nowhere, with a really diverse and complex cast of characters and surpised me with just how compelling it could be. Although the metaplot is not particularly complex, each story is very character-driven and interesting. Moreso when you realize that like the Osamu Tezuka-verse these characters cross a number of anime series. With the series' primary antagonist being the star of the later (and much higher budget) SKULLMAN anime.
However, still judging this on its own merits, Cyborg 009 is very good. It is rare we have a convincing reason for such a diverse and charismatic cast of characters. If this had of made it to the west in the 1980's, it would have changed the face of anime. However, because it didn't it was reduced to a little remembered action anime people saw a few episodes on Toonami.
If you love that classic anime feel, where heart, motivation, and the why was more important than how "powahful" a character is or how flawless the animation is, give Cyborg 009 a chance. Its one of the few series that was so good that it motivated me to track down the manga.