Anything run by Velo29 – although may not suit your location.. well run and well planned scenic routes.
They do some really quite nice events now – so many Sportive organisers went off into the realms of “bigger, harder, tougher, the toughest ever!” and while V29 do organise some pretty epic events, many of them are down at the more realistic / enjoyable end of the spectrum.
I did their York – Lincoln – York event (262km) a couple of years ago and the general organisation and atmosphere and support turned what could have been a pretty long and soul-less day out on a bike into something really quite fun.
I like the look of the Glorious Gravel, not got around to doing one yet.
Also worth keeping an eye out for some of the Gran Fondo events in Spain and France. Basically huge (mostly closed roads) sportive / race event, usually pretty cheap to enter. I did a 140km one in Southern Spain a month or so ago, featuring a 35km climb more or less from the start! There’s a well-known gravel event called Badlands out that way too, run as both an organised mass-start event but also a “free to ride whenever you want” thing. https://badlands.cc/