I’ve never knowingly seen a Saturday night cartoon in the UK. Simpsons and South Park were both on a Friday IIRC

We didn’t have Saturday nights cartoons in the UK when I was growing up. I used to love Ulysses 31 though

Not a cartoon, but I used to stay up late to watch Dark Angel with a then yet unknown Jessica Alba. The plot was pretty decent, and the writers were really good at keeping their ear tapped to the audience