Clocking in at 22 books, officially, with the almost prototypical Tintin in the Land of the Soviets republished late at Hergé's request and the unfinished Tintin and Alph-Art published posthumously in both sketch & script form and drawn by someone else, Tintin is surely the most long-lived comic book character, first seeing print in 1929, almost a decade before a certain Man of Steel on the other side of the Atlantic. Tintin spun out of a young readers' supplement in a Brussels newspaper and into his own magazine, full-color albums, cartoon show, films both live action and animated, stage plays, slash fic, a museum, and a plethora of merchandising.
And I dare say it is a deceptively rich work.
On the surface, Tintin owes as much to matinée adventure serials as Indiana Jones, and started off with picaresques that didn't make the most cohesive of graphic novels once collected, even if redrawn to format. Tintin's now controversial adventures in the Congo are a series of small incidents and great white hunter gags. His trip to America moves between gangland and western tropes. Cigars of the Pharaoh feels like three distinct adventures that nevertheless share a villain.
It's not until The Blue Lotus that the stories really seem designed, as we would say today, "for the trade". The Blue Lotus is a well-research exploration of 1930s China, with darker elements like opium dens and military insurrection, and while some racial caricatures remain unflattering at this point, Hergé means to revise the stereotypes his Western readers might hold true of "Orientals".
It's true that once he commits to a double act with Haddock, things take a turn for the better. The middle range of books are usually the most appreciated, blending high adventure with sci-fi and fantasy elements, with three double-sized adventures without a doubt the most memorable of the stories - The Secret of the Unicorn/Red Rackham's Treasure, The Seven Crystal Balls/Prisoners of the Sun, and Destination Moon/Explorers on the Moon (which is a lame title compared to the original French, On a marché sur la lune, "We Walked on the Moon", cuz yeah, Tintin beat Neil Armstrong to it by 15 years).
That's a musical term that translates blandly as a "pause", but more literally as melodramatic "tam-tam-tammmm" suspense notes played on an organ when something shocking is revealed in a film. Look at the bottom of every page, and that corner panel will always be a point d'orgue, i.e. a beat that makes you want to turn the page (again, this is a serial matinée thing). If the page is facing, the point d'orgue will be lesser, but be there nonetheless. Hergé saves his better ones for the right-hand page. And this isn't accident or instinct. When he redrew and/or re-laid out the pages for the larger album size, he sometimes added silent panels so that his point d'orgue would still fall on the same spot. This was a deliberate technique, and one modern comics creators could do well to study. Here are a few consecutive corner panels from The Black Island (selected the album at random) to show what I mean:
Recommendations: If you can only read one, go with The Seven Crystal Balls/Prisoners of the Sun.