It's no coincidence that I asked only a handful of people the same question and got the same answer twice. Megan of notmartha.org and Caroline of Whipped both recommended versions of these Liege waffles.

They are amazing. They are rich. They are not quick. They require special ingredients (Belgian pearl sugar, ideally, or sugar cubes such as these which you have smashed down to a suitable size).

They are worth making.

It almost goes without saying that they're probably better in a Belgian-style waffle iron. But the first time I made them, I used a conventional waffle iron and I didn't have any problems eating them.

Caroline's version can be found here. These are light and slightly yeasty, with delightful crunches of sugar. 

Megan's version is here. These are more breadlike, a bit more sturdy and substantial.