What theme parks over there I can visit that compare to WDW?
Off the top of my head:
Efteling in the Netherlands was a place that Walt Disney visited when he was researching places for Disneyland. Today, they have an incredible mix of fun roller coasters and dark rides in a beautiful green space. Their signature rides are Fata Morgana, a boat dark ride through the 1001 Nights on the scale of Disneyland Pirates of the Caribbean, Droomvlucht, a beautiful suspended dark ride and the Baron 1898, a highly themed Dive Coaster with a dark ride portion and insane theming. Coming in 2017 is Symbolica, a 35 million Euros (around 40 millions USD) high tech dark ride.
Here is a video of Fata Morgana:
Next, we have the Tivoli Gardens in Copenhagen, Danemark. It has been open for hundreds of years and in addition to rides, it is filled with restaurants and is a popular meeting place.
Here is a picture at night:
Port Aventura as someone else mentioned. It was built by Busch Gardens and Tussaud back in the 1990's. Universal then took over and now, the park has local owners. It has incredible hotels, a neat water park and are opening a third gate next year called Ferrari World.
Over in Germany, might I recommend Phantasialand? Located near Cologne, this park has some strict noise and visual restrictions which forced them to be quite imaginative. Whereas Disney just bought off the shelf spinning coasters, Phantasialand went with custom spinning coasters in a large building with elevators, moving track 12 years before Gringotts and other things. Their latest ride is Taron, an incredible launched coaster through a beautiful environment.
Taron.
Europa Park is currently the second most visited park in Europe, ahead of Walt Disney Studios Paris. Owned by a ride manufacturer, it is used as a showcase for their ideas and their hotels are incredible true 4 stars experiences.
This is a room at the "El Andaluz", an older hotel there.
They opened a pretty dark ride experience a few years called "Arthur- The Ride". They have a ton of dark rides, over a dozen roller coasters and their efficiently at moving lines make today's WDW pale.