Manga/Anime in America is pretty bad. I agree, most of the shit you find in Barnes and Noble is just awful, and I honestly haven't seen/read a good series in a while, but not all of it is crap.
Just to list some that I particularly enjoyed:
Neon Genesis Evangelion- The characters, the story, the themes.. it's all good. Action is really secondary to substance in this series. I think my favorite part of the series is reading/discussion/interpreting various aspects of the show- especially the ending (The End of Eva, haha)
Full Metal Alchemist- Characters are lovable, story is engrossing and mostly tragic in the end-- you definitely develop a connection with the characters in the show and you want to see it through to the end, no matter how grim it may be.
Death Note- this is the most recent series I've seen. I finished it during the summer 2007. This is writing at its finest. The premise is so ridiculous, yet executed perfectly so it keeps you wanting more. I've gotten people who think anime is a social taboo to watch the entire series and actually enjoy it.
Cowboy Bebop- Music + atmosphere + 4 great main characters and that lovable corgi, Ein. I think I read somewhere, possibly in a magazine, saying "Bebop made anime cool"; I think I have to agree.
Ghost in the Shell: Stand Alone Complex + 2nd GIG- I saw this through adult swim. The story can be hard to follow at times, but the writers went through great lengths to envision our world where cyborgs and humans with mostly cybernetic bodies are common. Animation is great, too. I generally don't like the sci-fi genre (which is where I think Ghost in the Shell falls) but this is a great series.
FLCL- so bizarre, the music is awesome. I loved it.
Paranoia Agent is also awesome. Lil Slugger is creepy.
As for manga, I haven't read any since like.. sophomore-junior year of high school, but there are some good ones out there. Azumanga Daioh is pretty funny and simple.. enjoyed it a lot. The Evangelion manga is really good, too.. follows the anime (which came first, I think) but differs at some points. It's definitely a different take on the series (for example, Shinji actually has balls in certain parts of the manga).
My guilty pleasure in manga is Love Hina

It was also the first series I ever read.
Anyway, those are most of my favorites. I haven't watched a new anime since Death Note and I haven't read manga in ages, but I don't really go out of my way to find them. Animes are just cartoons/animations and mangas are comics.. I don't view them as separate categories, but that's just me.
edit: i think I'm going to watch Gankutsuou now. It's an anime series based on The Count of Monte Cristo but set in the distant future. Seeing as The Count of Monte Cristo is my probably my favorite novel, I'm going to give it a shot.