Gaston is one of my favorites, laugh-out-loud funny as a kid and adult. Such great set-ups, visual gags, and word-play. For adventure, sci-fi, and incredible art, Yoko Tsuno was another great one that has stood the test of time. Oddly, I don't like Tintin as an adult, it's too whiz-bang and bumbling.
After growing up on European comics, the ones in the US were bland, just plain crude (Garfield), or overtly political (Bloom County, Doonesbury). The only one that had the equivalent depth and humor, while being uniquely American, was Calvin and Hobbes.
Speaking of crudeness, Hergé's worldview was pretty racist... Those first 9 albums or so are pretty cringeworthy. Especially considering that they've been rewritten a couple times to adapt to changing times.
Peanuts was in its prime before my time, but when I read it, it was cute but not funny. To me it seemed like a bunch of kids with adult neuroses, it seemed disconnected.
I loved the Far Side when it was at its peak in the late 80's, but it's just disconnected one-frame gags. And upon re-reading as an adult, they were very inconsistent, and the surrealism hasn't aged well. Maybe some comics just belong in childhood/teenage years, but it's clear that some really work for adults as well.
Family Circle falls into the cute one-strip category, but it didn't have much depth either--too saccharine. To me it didn't compare to European comics focused on family antics like Boule et Bill, or Mafalda (Argentinian).
I really think the American comics were hampered by the daily strip in the newspaper format. Many authors did try to make longer story arcs over a week of strips, and I preferred those. Calvin and Hobbes was the best at it, but there were other good ones such as Mutts and Over the Hedge. There were/are authors working outside the strip format, making whole book comics like in Europe, but I never got into those--too dark (Maus) or super-hero (Watchmen) or never-ending. For example, the more recent Amulet series started out well, but each book went deeper and deeper into the story and never really resolved the initial tension--I gave up after 7 or 8 books.
After growing up on European comics, the ones in the US were bland, just plain crude (Garfield), or overtly political (Bloom County, Doonesbury). The only one that had the equivalent depth and humor, while being uniquely American, was Calvin and Hobbes.