Hello! ^^ So I just recently got into drama because a friend told me about it and I started with k-drama which after a few good and entertaining titles like You're Beautiful, God's gift and I hear your voice, I just started to get frustrated with the genre to the point I had to give very low ratings to some of the most overpraised k-dramas and spent a good while to actually write reviews about it and say exactly what i found so wrong with them. I am a person that tries to watch everything with a fairly objective mindset, judging both the drama's quality and the entertainment it provides me separately. After one year and still not managing to get into it, I came to the conclusion that k-drama might just not be for me, maybe safe for some exceptions here and there, so I'm turning my head towards Japanese dramas right now with the hope that their storytelling will manage to satisfy me a lot more than what I've seen of k-drama (I fairly liked Flowers for Algernon and Library Wars already). Is there anything that you can recommend me from your J-drama experiences? Don't worry about genres or themes, at this point I'm open to anything. ^^ I just really want to know what j-dramas left an impression on you that's worth enough to remember. They can be popular titles or hidden gems, really, whatever you think it's worth mentioning ^^ 
Thank you in advance ^^
I think its depend on you :)
how far do you want to know and experiencing jdorama?
I think most of the popular jdorama knows by people are just a very little fraction jdorama wonder, so much jdorama beauty is hidden and most people never understand or never try to understand it

from me, at least try to watch some doramas from my list here :)

http://mydramalist.com/list/q1XzglP3

if you watch and love at least half of it, I think you will know better and deeper about jdorama
Thank you very much ^^ i shall give it a look.
A few of my recent favourites that have really stood out:

99.9: Criminal Lawyer (Law)
Okitegami Kyouko no Biboroku/The memorandum of Kyouko Okitegami (Investigation/Detective)
Kazoku no Katachi (Family/Friendship)
Fuben na Benriya (Comedy)
Bitter Blood (Comedy/Crime)

There are of course a lot more good and memorable jdramas (the classics like Hana yori dango, Hana Kimi, Pride, etc.) but it's been a while since I've watched them so I stuck to some of the ones I've watched within the last year. :) Hope you find something you enjoy! 
What I highly recommend are these:

Suspense, those dramas that you have to watch in one go because they're so good and interesting:
Kazoku Game
Maou
N no Tame ni

romance, not heavy romance a la Kdrama but more on the less annoying side:
The Memorandum of Kyoko Okitegami
Proposal Daisakusen
Buzzer Beat
Please Love the Useless Me

fun/friendship, you may think you're not into friendship dramas but jdramas will change your view on that plus the comedy is gold:
Gokusen
Nobuta Wo Produce
Hana Kimi (2007)
Legal High
My Boss, My Hero

or watch a movie:
Orange
Death Note (there's also a drama version)
Paradise Kiss
My Rainy Days

There are tons more but I'll leave it at that for now xD
JDrama can offer you a Japanese speaking drama!!!... 8D 
Suizokukan Girl, Futsu ga Ichiban and Senkai Musashi. Fresh serials for hot summer)
It's in your "On Hold"  list, but if you want a show that'll leave an impression,  Ouroboros in my opinion will do that for you, that is, in my opinion, an awesome show.   
I specially recommend suspense dramas, Japanese really know how to make suspense. You can watch:

*Maou
*Ryuusei no kizuna
*Kazoku game
*The Quiz show 2
*Bara no nai Hanaya
*Kurosagi
*Liar game
*Death Note (the movies)
*Suna no Utsuwa

For dramatic ones:
*1 litre of tears
*Taiyou no kisetsu
*Tatta hitotsu no koi

For romantic comedies:
*Hana Yori Dango
*Buzzer Beat
*Pride
*Hotaru no Hikaru
*Nodame Cantabile
*From five to nine
*Love Shuffle


I also think that K-dramas aren't for me. (I've only enjoyed watching two K-dramas.) I don't really like the atmosphere, the acting.. If I can recommend any J-dramas: Boku no ita jikan, Doctors, 1 Litre of tears, Koukou Kyoushi, Ghost Writer, Kyou wa kaisha yasumimasu, Lady Girls, Last Friends and Mutsu: Mieru Me.