Okay,

As the title states, I am looking for a manga, but especially a anime, that has a similar feel, or ambiance, to Witch Hunter Robin. I don't know exactly how to describe the similarity that I'm looking for. Maybe it's the slightly dark atmosphere without an overtly malevolent storyline, at least in the beginning. Or, maybe it's the character development that is very thorough and straightforward but not to the extent that it would throw it into the audience's face. Possible a bit of a slice-of-life story, maybe? However, it might be necessary for the series to be in either the fantasy or supernatural genre, but I am not sure if it would matter which one.

For an example,
The closest series to WHR that I can think of would be UDDUP, but it seems to lack a slight bit of mystery, which could have created a peerless series.

Hopefully this is descriptive enough for anyone that reads this far to get an idea of what I mean... if you do, hats off to you 'cause I think it's somewhat mangled.

Anyways, I wish you the best for allowing me some of your time that you could have used else where.

With Best Regards,
Toto

[color=green]"Officially, this machine doesn't exist, you didn't get it from me,
and I don't know you. Make sure it doesn't leave the building."[/color]

Perhaps Ergo Proxy or Chrono Crusade would fit in?

Other people (according to http://www.anime-planet.com/anime/witch-hunter-robin) would consider:
Hellsing
Wolf's Rain
Noir
Last Exile
....

Yeah, I would reccomend Ergo Proxy and Hellsing as well.

[img]http://i196.photobucket.com/albums/aa229/azrinirza/makotoshinkai1_zpse3901c5a.gif[/img]
Everyday I'm tumblin'

Black Blood Brothers (novel) but its a novel
more vampire oriented but find yourself a copy and translate! ita fuckin worth it!