Also 'findable' : The Clangers (charming 1970s show from the UK); Mr Men; Shaun the Sheep; Mr Benn.
All of these are 'gentle' but fun, and not really educational per-se. Even though you'll end up watching all of these again-and-again, Shaun the Sheep remains entertaining for parents too.
* https://en.wikipedia.org/wiki/Kipper_the_Dog
* https://en.wikipedia.org/wiki/Clangers
* https://en.wikipedia.org/wiki/Mr._Men
My wife and I are working through the old Tom and Jerry cartoons with our toddler, and we are shocked to see how much blackface there is. Like, okay, I get it was a different time- but the quantity is shocking. Episodes where it doesn't even have to happen, they'll just quickly mock black people and then get back to the plot.
If you want a complicated viewing experience, track down Clampett's "So White An' De Sebben Dwarves", which is positively bursting with energy and love, for both the craft of animation, and the jazz scene of the day... and a whoooole lotta visuals that just aren't okay any more.