I guess the titles more likely to interest me on the list I've already read, but while you're in the vein between Calvino and Carroll (wide ground, I know!), you might want to give a try to Boris Vian one day. He remains way too little known by anglosaxons (despite the heavy influence of Carroll and Swift on his writing, and despite he was a huge americanophile)

His most acclaimed novel (posthumously. None of his novels under his own name had much success in his lifetime, unlike those he wrote as Vernon Sullivan, fake American crime novels he pretended to be the translator of) would be "L'Écume des Jours", which became an iconic novel of May 68 (as the incarnation of the "L'imagination au pouvoir" slogan), though L'Herbe Rouge, which deals with darker, more serious themes under the fantastical elements and humour might be more your cup of tea - and its fits square into the spec fic genre, with his SF elements and weird universe (it's my second favourite after L'Automne à Pékin, in which the protagonist takes the bus to work one morning and and end up instead in a desert where an extremely weird cast is building a train line to nowhere that ends up in nothing at the end.).

I don't know if bilingual editions of his novels exist, though I guess he might be worth cheating one using a French edition and an American edition (he's getting translated in English in recent years) if they don't. He might be challenging in French only - so many wordplays, semantic shifts, fanciful plays with syntax and spelling. One example from a chapter I read yesterday: the protagonist enters a room where his friend and his lover where just having sex. The girl turned on her heels (tourné les talons) and left the room (trying to ajust a skirt that isn't in the mood because it was in the middle of a conversation with a coat left on the bed) Vian will rather write "lorsqu'elle eut tourné l'étalon", ie: after she had gone around the stallion). That one's pretty obvious, but Vian's the sort of writer with which you need to read every word on the page or he rapidly loses you (and he tries to!) His novels (but one) are really short, though (about Le Petit Prince short).

Better read with some Duke Ellington in the background, for the proper mood.

If one has to pick only one novelist from the 1940s in France that'd be Camus, but Vian ought not to be far behind, IMO. He's certainly the most imaginative and playful writer from these decades, with a jazzy and very musical prose and not without some depth underneath the more farcical elements (as alas few like Queneau and de Beauvoir saw in him in his days. A reviewer had even dismissed him as "the Pope of Existentialism's altar boy". Another called him Sartre's pet monkey! Most of his contemporary reviewers discussed more the public figure Vian was at St-Germain than his books.)

He's got his revenge though. Unlike most of his "stuffy" contemporaries that got long forgotten, he's still widely read today (he's more read than Sartre's novels, even), many writers claim him as a major influence, covers of his songs are still recorded, his plays are still mounted on stage at home and abroad (especially his anti-war ones recently), he's become one of the most popular French writers post-1990 in eastern Europe (a phenomenon the Vian scholars are still a bit puzzled over) and though he's attracted scholarly attention and enthusiasm long ago now he's "made the big leagues" with the literary establishement by being this year's new entry in La Pléiade (right on Camus's heels). I went in to buy the Borges (now back in print) but just couldn't resist postponing that purchase when I saw Vian had made La Pléiade.

I think you'd have the right interests/frame of mind to have fun with Vian despite the language barrier. He certainly had his unique kind of "speculative fiction".