What are some very good anime I can watch?

Questions like these are harder than the Tests. Well, there's a lot of them:
Sci-fi/Magic: K, Red Data Girl, Accel World, To Aru Kagaku No Railgun, Suisei No Gargantia, To Aru Majutsu No Index, Sword Art Online, Hataraku Maou-sama, Soul Eater, Fairy Tail, One Piece, Shakugan No Shana,
Violence/ Horror: Another, Jigoku Shoujo, Shingeki No Kyojin, Gosick, Magi, Kamisama No Memouchou.
Romance: Maid-Sama, Kotoura-san, Special A, Ouran Koukou Host Club, Kami Nomi Zo Shiru Sekai, Lovely Complex, Bokura Ga Ita, Hayate No Gotoku, Toradora, Zero No Tsukaima, Acchi Koochi, Amnesia, Kimi Ga Nozomu, Yahari Ore No Seishun, Hataraku Maou-sama!
Comedy: (Mostly are from The Romance Section) Lucky Star, K-ON!, Fairy Tail, Soul Eater, Gintama,
Sad/ Tearjerkers: Clannad, Air, Angel beats, Anohana, Little Busters, Naruto, Fairy Tail, One Piece.
Music: Idolm@ster, K-ON!, Akb0048, Love Live: School Idol Project! Uta No Prince-Sama!,
There's more than that, but I forgot it. Sorry. :$
(The photo below is a tearjerker anime named Anohana. I suggest you to watch this first. Be warned that on the first episode, it might be boring and lame, but it'll later gets more epic and you will cry like a BOSS)

K-on!! its my ultra favorite anime!! XD (in pic.)

Black ★ Rock Shooter!!
Hayate no Gotoku!
Azumanga Daioh!
Lucky Star!
Fairy Tail!
Working!
Morita-san wa Mukuchi!
AnoHana!
Cardfight Vanguard!

and me too i havent watched THAT much anime's yet,so were the same =)

not really sure what your tastes are, just going by what i see you liked and keeping with that level of extreme lol

*The Girl Who Leapt Through Time (movie)
*Summer Wars (movie)

*Uta no Prince-sama
*Blue Exorcist
*Vampire Knight (may want to try reading the manga 1st, sexier XD)
* Tiger & Bunny
*Black Butler (highly recommend the manga)
*Code Geass, one of the best anime ever..
*Trinity Blood
*Mushi-Shi
most are action/adventure/supernatural and/or with light romance.

and you might possibly like psychological thrillers/supernatural
*Psycho Pass
* Darker Than Black
*Baccano! (by the same author as Durarara!!) warning: is extremely violent and very fasted paced

hope you find something you like :)

Blue Exorcist

Hm, it's hard for me to suggest animes to people if I don't know the animes they've watched but...I know you like Hetalia so I would recommend Ouran High School Host Club~ It's a really good comedy, one of the funniest I've seen XD And it can be really random at times and all of the characters and really lovable <3
I'm sure you'll like it =)

You should totally watch Fairy Tail!!! Such a awesome anime! :D Its about a teenage wizard named Lucy Heartfilia who wishes to join a wizard guild, later on, she meets a young man named Natsu Dragneel and a talking cat named Happy :) They formed a team with other two members and they go on crazy yet awesome adventures X3
Also watch the EXTREME anime Katekyo Hitman REBORN! Its about a 14 year old boy named Tsunayoshi Sawada who is becoming the next mafia boss of the Vongola Family. A baby comes to his house named Reborn who is going to train him to become a strong and loyal boss. At his school, he is known as No-good Tsuna. Im gonna right there ^^
Other animes to watch~
Amnesia, Kuroko no Basuke, Gintama, Durarara!!, Magi, Cardfight! Vanguard, Another, Kaichou wa Maid-sama, K-ON!, Okami-san, Sword Art Online, Kimi ni Todoke, Uta no Princ-sama, Soul Eater, Bamboo Blade, Vampire Knight

Black Butler - mystery
Death note - Mystery
Kimi Ni todoke - romantic comedy
Maid sama -Romantic comedy
Vampier knight - romance
Blue exorcist - action

- Accel World
- Acchi Kocchi
- Kimi ni Todoke
- Gintama
- Ao no Exorcist
- Kuroshitsuji
- Clannad
- Kanon 2006
- Air
- Mirai Nikki
- Another
- Anohana
- K-ON!
- Angel Beats
- Vampire Knight
- Monster
- Denpa Onna to Seishun Otoko
- School Rumble
- Sola
- Kaichou wa Maid sama
- Pandora Hearts
- Black Rock Shooter
- Death Note
- Hyouka
- Lucky Star
- The Melancholy of Haruhi Suzumiya
- Code Geass
- Durarara!
- Kuroko no Basket
- Boku wa Tomodachi ga Sukunai
- Soul Eater
- Kuroshitsuji
- Amnesia (psst hot guy alert)

i hope that list helped ^_^ enjoy watching them~

and here's some eye candy, expect more of this in the wonderful world of anime

hmm.. i recommend these:

> Black ★ Rock shooter
>Shakugan no Shana
>Death note
>Fate/zero
>Kamisama Hajimemashita
>Mirai nikki
>toaru majutsu no index
>Gosick
>Guilty crown
>Zero no tsukaima
>Kaichou wa maid sama
>Romeo x Juliet
>Highschool of the dead
>Hyouka
>Fairy tail
>Inuyasha
>K-on
>Clannad and Clannad afterstory
>Angel Beats!
>Detective conan
>Magic Kaito
>Another
>Sword Art online
>Pandora hearts
>Elfen Lied
>Kampfer
>Ranma 1/2

I forgot the others, mehehehe, sorry... But if you're still not satisfied with what i have given, feel free to drop by and ask me :D

Pic: Mirai nikki :D

The top 3 leading animes animes..............

1)Bleach
2)Naruto + Naruto Shippuden
3) One Piece

Since you are a fan of Durarara and Detective Conan,
you might like Zetsuen no Tempest.(picture)

My favourite anime are Gintama, Reborn and Beelzebub!!!

Iuyasha
Fairy Tail
Bleach
Fruits Basket
Angel Tales