Gravity Falls: I actually like it way more than I thought I would.
Plot: Inquisitive little boy and wacky little girl (fraternal twins) move in with huckster great-uncle and uncover supernatural/paranormal mysteries. Monster of the week-type stuff. Nothing amazing but solid popcorn fare.
But it steadily gets better and better. The jokes get better, supporting characters get fleshed out more, freakier mysteries, plus a couple overarching plots. Slenderman even makes a cameo in an ostensibly children's cartoon as well as the voice actor for Morty from Rick and Morty. Plus, dat season 1 finale and season 2 opener. Now, I can't wait for new episodes.
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