Flying Dutchman definitely and Symbollica are stand out new attractions. Honestly the park must just not be your bag, which is fair enough, it's an incredible park with such a stellar range of old and new and a unique style. It ticks boxes for good coasters too with Baron and Joris (better than their Alton Towers equivalents) but obviously is more about the park itself and the dark rides than coasters. There's Phantasialand across the border for that!
I've only been once but I love Efteling, it is a beautiful and somewhat unique park. I am very much looking forward to visiting again later this year. I do however agree with the comment that they are lacking a real standout attraction.
DVH has a brilliantly themed dark ride section but the coaster is a bit pants. Symbolica is good, but I feel it is just lacking something. Baron looks stunning but at the end of the day it is a mini B&M Dive Machine and they are just fine; Oblivion is better track and train in my opinion. Joris is great fun but not on the same levels as say Troy or Wodan.
I'd love to see Efteling get a truly top coaster that will make everyone stop and look, but I just don't think it is their style. And that is fair enough.