What's the best manga you've ever read? and why do you think that's the best one?

It all depends the genre of manga. It's extremely hard to choose only a few but my favourites in every genre are actually (there dont be the same tomorrow I'm sure but Well)

Shounen / Seinen :
- Action / Badass characters : http://www.mangago.zone/read-manga/burning_effect/?EZiT
- Fantasy / Dungeon / Weak-> Strong : http://www.mangago.zone/read-manga/solo_leveling/?UXeY
- Apocalyptic / Great plot / smart Mc
http://www.mangago.zone/read-manga/omniscient_reader_s_viewpoint/
- Comedy / Prison / Action
http://www.mangago.zone/read-manga/nanbaka
- Fantasy / Supernatural / Secret Identity / Demons :
http://www.mangago.zone/read-manga/black_haze/

Shoujo / Josei :
- Reincarnation / Isekai / Romance / Comedy :
http://www.mangago.zone/read-manga/miss_not_so_sidekick/?w2EC
- Romance / Realistic / Cute /
http://www.mangago.zone/read-manga/the_lady_and_her_butler/?Rl2c

Yaoi / Shounen Ai
- Realistic / Poetic / Pure love
http://www.mangago.zone/read-manga/life_senjou_no_bokura/
- Funny / Cute / Shounen Ai
http://www.mangago.zone/read-manga/19_days/
- Psychological / Horror / Yaoi
http://www.mangago.zone/read-manga/black_mirror/
- Realistic / Break up / Shounen Ai / Time travel :
http://www.mangago.zone/read-manga/this_ending/
- One shot / Tragedy / beautiful / Romance / Shounen Ai :
http://www.mangago.zone/read-manga/the_specific_heat_capacity_of_love/

It's to hard To choose I would like To put like 50 others but Well I Will stop (⌒▽⌒)

wow i'll take a look at those ones :00
thanks for sharing!!

On doorstep
+ Drama / Romance / Slice Of Life / Yaoi

http://www.mangago.zone/read-manga/on_doorstep/

I like this one because it has a very interesting plot, a unusual couple development and the art is also very pretty. Also, this author (Chongtak) is my favorite. I recommend all of her pieces (Loplop and Midnight rain are great).

The Perfect Relationship
+ Yaoi / Psychological / Drama / Webtoons / Tragedy

http://www.mangago.zone/read-manga/the_perfect_relationship/?oXTb

This one is avery engaging drama. It's very interesting and it has an awesome plot twist.
But it tackles some triggering topics such as bullying and trauma, and the relationships are pretty f*cked up. So please, don't read it if u feel uncomfortable about topics like these.

Beloved (jaeliu) Manhua
+ Yuri / Webtoons

http://www.mangago.zone/read-manga/beloved_jaeliu/

Intriguing story and unique art style. The erotic scenes are fascinating and the couple is also very cute even though there's a age gap between them.

Love or Hate(Yeongha)
+ Yaoi / Drama / Romance / Adult / Webtoons

http://www.mangago.zone/read-manga/love_or_hate_yeongha/?EOgJ

The art is awesome, the main character is very captivating and the way the author developt the love triangle it's very interesting (i love the tension between the three of them).

Killing Stalking
+ Drama / Horror / Mature / Psychological / Webtoons / Yaoi

http://www.mangago.zone/read-manga/killing_stalking/?3tqg

Well, that's a very polemic one but for sure is my favorite. It's an awesome Psychological Thriller Horror. It's dark, twisted and pretty f*cked up. This is not a yaoi, even though it portraits the relationship between Sangwoo and Yoonbum (they aren't suppose to be cute together). The characters development is incredible and it's the most thriller story ever.