PLEASE DON'T PUNCH MY TEETH FOR SOUNDING LIKE A HIPSTER
Basically, I'd like a compilation of the most bizarre mangas you've ever come across - bonus points if it's got a deep and intricately executed story line or is a social commentary of some sort.
I'll set some limitations so that 1) I don't get mostly "some what strange" works and 2) can proudly put into light genres and themes that terrify me (I don't like being terrified!)

• I'd like to ask that any temptations leaning towards shoujo and shounen genres be dismissed.There may exist a very small minority that fit into my 'bat-shiz-crazy' boundary but the VAST VAST majority are dissatisfying pieces with story lines that do the unspeakable: vary just slightly from heavily overused cliches and plot devices.
• I don't mind sexual themes so long as they don't get overly graphic - das gross bro.
• PLEASE BE LIGHT WITH GORE AND MACABRE. THAT BIT GIVES ME NIGHTMARES.
• Comedy is more than welcome.

So that's it folks! Now Mush!

Mushishi
Onani Master Kurosawa

Kokoro no Kanashimi - a darker look at human psychology.

I Am a Piano - anthropomorphic observations

"Pup" Ponders the Heat Death of the Universe - short unusual webcomic

Nickelodeon - many strange oneshots

Oyasumi Punpun - haven't read much, but I've heard it's good

Hirameki Hatsume-chan - cute and weird

Uzumaki - horror

Olimpos - very philosophical and contemplative

I Am a Hero - been a while, but I think it fits

A lot of these mangaka have created more strange works, so I suggest looking into those as well.

Vampire Juujikai
If you ask me... its a seinen not a shounen.

It'd help if you gave some examples too y'know!

Is this me in a nutshell?
Pretty much.
[img]http://www.dragonflycave.com/wpay/ninetales.gif[/img]

Moon Child
Kaguya Hime
Drifting Classroom
Fourteen
Helter Skelter
River's Edge
Devilman

anything else in my batshit insane list.

[img]http://oi50.tinypic.com/1p7xj6.jpg[/img]

This is really, really broad, you know?

I guess I'll just aim for the social commentary/psychological manga (with some really plotty/political ones thrown into the mix).

Bokurano
Cesare
Franken Fran (yeah, it's shounen, but it has one of the best social commentaries I've ever had the pleasure to read in manga; there is definitely gore though, so watch out for that)
Dusk Story - Tasogare Monogatari (and basically anything else Tono writes are great; they're not intricate but they have excellent atmospheres and are great examples of the bizarre in the everyday)
Gunka no Baltzar
Gunslinger Girl (definitely reads more like a seinen than a shounen)
Historie (oh and Parasyte too; there's gore in both though)
Kagerou Nostalgia (a shounen but a very good shounen)
Kenja no Ishi
KissWood
Shoukoku no Altair
Vinland Saga
Yume Tsukai (if you want bizarre, this one's definitely for you!)
Yumekui Kenbun

Seconding Vampire Juujikai (and everything else Shirodaira Kyou has ever wrote).

Wendy - Don't even ask what this is about

What a wonderful world Social commentary but may be considered mainstream

Centaur's Worries Adorable, weird, and one of my favorites

Shi ni Itaru Yamai
Husky and Medley
I'd say many stuff recommend here are mainstream, but probably I've a different conception of what mainstream is. And I'm not even sure my suggestions can be considered not mainstream.

What I like in Trivial Pursuit style. Pick your category:[img]http://i379.photobucket.com/albums/oo233/Reid4891/Manga/trivia-1.jpg[/img]

Danshi Toilet de Machiawase its weird but good.

G Senjou Heaven's Door unusual plot.

Kaikisen satoshi kon...nuff said

Onani Master Kurosawa second this

You might try City of Dead Sorcerer. There's some gore but nothing extreme. Nothing else really that I can think of off the top of my head.

Freesia
Sekine-kun no Koi
Vinland Saga
Doctor Du Ming I'm quite not sure about this one since I didn't actually read it, tho I heard it's quite good.
Jiraishin It's been sooo long since I read this, but I think it may be to your liking.

as the request is as far from mainstream as possible, this one fits the perfect fit:
asuka hybrid
http://www.mangaupdates.com/series.html?id=46224

Kokumin Quiz actually fits a lot of the requirements...

• pretty crazy, and the art doesn't hurt
• comedic
• social commentary

Akumetsu tha end 😀

Non mainstream manga with most unusual plots/concepts:
Halcyon lunch-crazy but hilarious XD
Doll star-psychological and weird.
Golondrina-suicidal lesbian matador, need i say more? XD
No.5-very weird....
Sabaku no tami-not your usual tale and the layout is abnormal as well.
Kimi no kakera-its got some mainstream elements but the execution makes it unique...and I can never figure out what its target audience is =__= it seems too perilous and cruel to be aimed at kids and yet...at times it reads like a kids fairy tale...plus its really existential...
God pretender-it starts out and you think yeah...this is just another martial arts manhua but as it goes on more and more elements pop up and it’s like whaaaat.

Others that are unusual/not mainstream:
Yokokuhan
Kizu
Demon flowers
Baku
Magic
0 no Soukoushi
Route 20
Mukashi no hanashi
Beautiful people
Watching TV all day makes you stupid
TV eye
Kingdom of stars
Shuna no tabi