Something that's good and can be cliched BUT needs to have at least one part that is completely unique and original.

Beast Master
Auto Focus
Matsuri Special
Crimson Hero
Five
Aishiteruze Baby
Tenshi Ja Nai!!
Charisma Doll
You're My Girlfriend
Stroke Material

all of these have parts that are super cliché, but they also have some unique parts to them too.

H2O <-- is manhwa okay?
Mekakushi no Kuni
You're So Cool <-- also a manhwa
Suki ni Natte mo Ii no?
Forever Honey <-- tear jerking oneshot
Hotarubi no Mori e
Magic
Help!!
No Title
Sekai no Chushin de, Ai wo Sakebu

Those manga have that 'unique and original' factor or me. But since I don't know what you specifically mean... Hope it suits your tastes.

And try Kayono's works. Smutty as hell, but good.

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Current avatar features Badou from Dogs.

cool, there's enough shojo'y goodness here to make my balls atrophy and make me grow boobs, I'll check out a few of ur suggestions

why has skip beat not been mentioned? D:

Although it may seem as you typical shoujo manga (possible love triangle and all), the very perceptive heroine of the manga may make you think otherwise. Very hilarious.

Devil and her Love Song

Seconded!

Also, how about trying:
Carat! <== hilarious parody
Tamago no Kimi

Both are some of my favourite and definitely unique.

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Lovely Complex
Heaven!!
Anti-Gravity Boy
Peter Pan Syndrome

hmmm, i wanna put Power!! here, but i can't think of anything unique about it other than her character... but i guess that's good enough? this is one of my favorites



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Ah..most of the ones I wanted to say already got mentioned.
Diamond Head - Personally I only thought this was only so-so but you never know..
Tokage Ouji - Well, lizards are pretty original..It's pretty cute, not much depth to it
Good Luck - I suppose the main character herself is the main asset to originality
I also second Akuma to Love Song, Mekakushi no Kuni and Beast Master

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"If it's bitter at the start, then it's sweeter in the end.."