If the Great Heidelberg Tun had a stroke...

 Les Misérables is the Great French Novel - I would also say Gargantua and Pantagruel fits the bill, but that one is a pentalogy saga, and Les Mis is a standalone. And I adore the Friends of the ABC and especially Courfeyrac and Grantaire <3 kyun (I am in the Les Mis fandom for a reason).

Courf is basically your garden-variery shonen protagonist crossed over with a 007 or similar British man of wealth and taste, and a little with Quentin Tarantino. A keet with a kitten motif, a Gascon who truly embodies the regional stereotype - he even has the sword cane for a musketeer or knight in shining armour! - and with a great sense of humour (always with a quip or pun on his lips). Add a little Mercutio to the Courf formula, and you have a character I completely identify with...

but, if Courfeyrac is my idealistic side, Grantaire is my cynical side, a depressed alcoholic artist (from Marseille in my headcanon), in unrequited love with the ephebe of a leader (I coined the term "Enjolsexual" for a good reason), an epicure and a comedian like Courf but it's only a mask in R's case (he signs only with a capital R, une grande R!).

In the dramatis personae "A Group which Failed to Become Historic," Hugo introduces us to R by mentioning his good taste in food and beverages, his knowledge of the Parisian nightlife...

Among all these passionate hotheads and true believers, there was one

cold-blooded skeptic. How did he get to be there? By juxtaposition. This skeptic’s name

was Grantaire and he normally signed with this rebus: R, for grand R,

capital R. Grantaire was a man who took good care not to believe in

anything. And he was one of the students who had got the most out of his

studies in Paris; he knew that the best coffee was in the Café Lemblin and

that the best billiard table was in the Café Voltaire; that you got good pancakes

and good wenches at L’Ermitage on the boulevard du Maine, the best fried

chickens at mère Saguet’s, excellent eel stews at the barrière de la

Cunette, and a certain light white wine at the barrière du Combat. For

everything, he knew all the best places; he also knew how to kickbox, both savate and chausson marseillais, and

make his way around a tennis court, a gymnasium, and a dance floor, and he was a natural

with a singlestick in stickfighting. A big drinker to boot.

And him being an "Enjolsexual:"

Still, this skeptic was fanatical about one thing. This one thing he was

fanatical about was neither an idea nor a dogma, neither an art nor a

science; it was a man: Enjolras. Grantaire admired, loved, and venerated

Enjolras. Who did this anarchic doubter rally to in this phalanx of

absolutists? To the most absolute. In what way did Enjolras enthrall him?

Through ideas? No. Through character. A phenomenon frequently

observed. A skeptic sticking to a believer—it is as elementary as the law of

complementary colours. What we lack attracts us. No one loves daylight

more than the blind. The dwarf girl adores the drum major. ...

Grantaire, in whom

doubt lurked, loved to see faith soar in Enjolras. He needed Enjolras.

held spellbound by that chaste, healthy, firm, upright, hard, candid

character. He admired, instinctively, his opposite. His limp, wavering,

disjointed, sick, deformed ideas attached themselves to Enjolras as to a

backbone. His moral spine leaned on that firm frame. Beside Enjolras,

Grantaire became somebody again. He was himself, in any case, composed

of two apparently incomptible elements. He was ironic and warmhearted.

His indifference was loving. His mind could do without faith, but his heart

could not do without friendship. A profound contradiction—for an

affection is a conviction. That was his nature. Some people seem born to be

the verso, the reverse, the flipside. They are Pollux, Patroclus, Nisus,

Eudamidas, Hephaestion, Pechméja. They can live only on condition of

leaning on someone else; their name is a sequel; their existence is not their own; it is the

other side of a destiny that is not theirs. Grantaire was one of these men. He

was the flipside of Enjolras.

Grantaire, as a true satellite of Enjolras, dwelt in this circle of young

men; he lived there, he was only happy there, he followed them

everywhere. His great delight was to see those silhouettes coming and

going in the haze of wine. They put up with him because of his good

humour.

The believer in Enjolras looked down on the skeptic Grantaire, and the teetotaller

looked down on the drunk. He would dole out a dose of pity from on high.

Grantaire was a Pylades who did not pass muster. Always treated roughly

by Enjolras, pushed away harshly, rejected yet coming back for more, he

would say of Enjolras: “Such a beautiful slab of marble!”

But it is R's first words, his Establishing Character Moment and the start of his epic rants, that truly solidifies his character. Grantaire is introduced using a very surrealistic metaphor (is it the absinthe or his own creativity)?

“I’m so thirsty! Mortals, I have a dream: that the Great Heidelberg Tun has a stroke,

and that I am among the dozen leeches they apply to it. I want

to drink. I want to forget life. Life is a hideous invention of who knows

who. It doesn’t last two ups and it’s not worth two ups. You break your neck

trying to stay alive. Life is a stage set where nothing much actually works.

Happiness is an old theatre decor, painted on one side only. Ecclesiastes says:

Omnia vanitas, ‘All is vanity.’ I couldn’t agree more with the poor bastard, if he ever

existed.

The Great Heidelberg Tun is the biggest barrel in Europe, located in the cellars of Schloss (Palace) Heidelberg, and always full of good wine. Its size is 7 m long and 8,5 m wide, and its volume is 220,000 litres. There is even a dancefloor on top, and young people dance on it during certain festivals! 

The Tun appears so often in the literature of Romanticism that it has become a meme. For instance, in Moby-Dick, the spermaceti gland of a sperm whale is compared to the Great Heidelberg Tun, being around the same size and also full of a costly liquid. Heidelberg being the Capital of Romanticism, many Romantics either visited the town or studied at its university, the Ruperto Carola, and they had surely danced on the Tun and the image stuck with them:

The Tun is referenced in Rudolf Erich Raspe's The Surprising Adventures of Baron Münchhausen, Jules Verne's novel Five Weeks in a Balloon, Victor Hugo's Les Misérables (in Grantaire's rant, here), Washington Irving's The Specter Bridegroom, Mary Hazelton Wade's Bertha, Mark Twain's A Tramp Abroad and Wilhelm Busch's Die fromme Helena. It can also be found in Herman Melville's Moby-Dick as well as in Lyrisches Intermezzo by Heinrich Heine, later used in the song cycle Dichterliebe by Robert Schumann for the final song "Die alten, bösen Lieder (The Old Evil Songs)". 

(Great Heidelberg Tun. Notice the dancefloor on top!)

Leeches were used then to cure multiple diseases, the prevalent theory of disease being the four humours (fluids): these worms were used to "leech" away superfluous fluids that made the patient ill. Stroke victims in particular were treated with leeches, although this was mostly ineffectual...

If the Great Heidelberg Tun, personified, had a stroke, think of how many wine-thirsty leeches, eager for fine Rhine wine, would be applied to it! And obviously our lovely cynic Grand'R would loooove to be one of them!