What are some good manga?

I really liked Uzumaki and Death Note. Both are sort of horror though, not sure if that's your thing or not.

 

If you want a really long story, go for One Piece, the gift that just keeps giving.

 

Some of my favorites are fullmetal alchemist, noragami, and soul eater and I second death note. I also liked d.gray man and black butler. I'm blanking on other ones, but I'm sure I could think of more. Hope that helps

 

Fullmetal Alchimist was my favorite ^^ And GTO is a lot of fun, if you're not easily shocked...

 

Fullmetal Alchemist, Neon Genesis Evangelion, Berserk.... I've read so many I just can't think of them right now.

 

If you're looking for something LGBT (and more specifically Trans) Friendly, go with Wandering Son. Link: http://kissmanga.com/Manga/Hourou-Musuko

There's also Tokyo Ghoul and by extent Tokyo Ghoul:re which includes 3 Trans characters, but only one of them isn't a stereotype/joke character and he doesn't appear until Tokyo Ghoul:re. Link: http://kissmanga.com/Manga/Toukyou-Kushu

 

Hourou Musuko and Fullmetal Alchemist^ seconded.

 

As you can probably tell from the replies, Fullmetal Alchemist is a pretty vital manga to read! I'm also a fan of Kekkaishi(Action), Death Note(Thriller) and Nichijou(Comedy)

 

Hunter x hunter all the way

 

Death Note is awesome (although it's more Crime/Thriller than Horror).

If you want:
Romance - Mars (tw: rape, suicide, and violence; otherwise a great 'Beauty and the Beast' story about an artist and a motorcycle racer with a deathwish)
Fantasy - Yu Yu Hakusho (great fighting manga with demons and alternate dimensions and stuff)
Slice of Life - Horimiya (another romance but it's literally just two teenagers that start dating, they make curry, watch horror movies, and talk to their friends)
Crime - FAKE (Boy Love! tw: lots of blood, death, murder, drugs; decetives falling in love and kicking ass!)
Sci-fi - Gundam Seed (gundam is fairly self-explanatory...right?)
Sports - Chihayafuru (technically a girl's comic, about competitive karuta, lots of Japanese cultural things, very interesting)

Also fairly popular right now:
Sword Art Online (life in a vr game), One Piece (pirates!), Kagerou Project (singing), K [Project K, Kings] (superpower gangs), Haikyuu (volleyball), Kuroke no baseke/The Basketball Which Kuroke Plays (basketball), Noragami (gods),...