For almost any anime, I recommend the Manga over it. The big problem with MOST anime is the filler, how episodes are made longer and ones are completely made up. The three best examples of this I know are Naruto, One Piece, and Bleach, which are all FAR better mangas. And don't anyone DARE watch the English version of One Piece. Any interesting or funny parts are destroyed by what might be the worst dubbing ever.
And think Full Metal Alchemist was good? I was. Really good. But the manga completely blows the anime version out of the water. That's true for most, but sometimes you get an anime that you can tell is meant to be seen in motion.
My favorite anime is FLCL, but Cowboy Bebop and some others are way up there. FLCL has a really cool Manga, but it tells a different version of the story and in a very different style. I like the anime more. Eureka Seven has some absolutely incredible moments, but I wasn't impressed by most of it. The Manga so far is doing a better job of telling a better version of the story, but it misses out on the really great action sequences. Ghost in the shell was interesting, but after seeing the first two movies, I think I have to watch the show, because I feel like I'm just not getting anything out of it.
Berserk and Gantzs are the most violent mangas I'm following, and they're pretty good. It's a nice contrast to the younger manga I read. O haven't seen the anime versions, so I'm not sure how they go. I think Gantz is a whole lot more disturbing and interesting though, especially for programmers like many of us here.
Another reason to go with manga is time. Specifically, unless a manga is as text heavy as Death Note, you'll get the story faster, because it isn't forced to drag a certain amount though 24 minutes or so. I read all of Berserk up to the most recent in 3 days, while still going to classes and doing my work. That's a good 300 chapters, meaning over 6000 pages.
As for American anime? Avatar is pretty good, and the animation is far better than most Japanese anime.
If you like anime-styled games, No More Heroes is amazing. That's a game for real gamers, the kind who like games that they really have to work to beat. It's the first game I've ever played where halfway through I was almost twice as good at every other game I played just for playing that one. And it's got style up the wazoo. It could easily have been an anime, if the gaps in the city part were made into a linear story.
Edit: I'm going to be getting Killer 7, because it's also made by Suda 51 and looks to be worth while.
BlockVerse-> Old School Beta Demo-> Dream-> Old School-> Guitar Platformer
