I think I qualify as an 'Old-taku' now....
well, here goes nothing!
Kodocha. Very silly as an anime, but very good nonetheless.
Shiki. It's advertised as horror, but it's more of a mystery, (to me), and explores deep concepts.
Mononke. NOT princess mononke, though that is a good movie. Mononoke is about a priest traveling around japan and excersizing evil spirits. I found it because I listened to its soundtrack first, but the anime is an artistic thrill and the stories are always very captivating.
Hell Girl. At first, I was just watching for fun. It's not...horror, it's just very interesting. But once the end of the series hit me, it hit me HARD. Very good.
Mushishi. Haven't seen the second series yet, but the first was very good.
Cowboy bebop - a classic story, and a cornerstone in anime history.
Puelli Magi Magica Madoka. If you don't want to watch it, go listen to the soundtrack, because that was enough to captivate me
There's more, but I need to get to work. Those are just three that come to mind. I might come back later and add more to the list. I tend to like more obscure things, because I sort of watched all the really popular anime series already xD
--side note--
I'm also a horror fan, but it takes A LOT to make me scared. So the two up there that are horror could potential scare SOMEONE, I'm sure. So...be weary before watching. I guess I don't consider something horror unless it scares me, and those two didn't really, but they could and they both use a lot of horror elements. Particularly Mononke. I've just seen a lot that scared me, so these shows that use classic tricks are interesting, but not scary, to me.
