I had a neighbor who had a pug. She would have to use a q-tip to constantly clean the folds of the skin on the face for health reasons. I've never had to do more that give a dog a bath so I was wonder what dog breeds have you had that needed extra tlc to maintain their health and good looks?
None of my dogs I have so far needs more grooming than an usual good bath. Perhaps the boxer gave a little more of work since it drools more than other dog breeds, but is nothing really complicated to handle.
I only know that Shih Tzus and Poodles require more care than other breeds, especially when the hair is kept long. They need daily brushing and regular haircuts to avoid tangles. I never liked poodles for that reason.
Poodles do seem a handful. Their curly fur can be a hassle and if you don't have a lot of time at your disposal, you could end up neglecting them. I do think Collies and Mountain Dogs should be added to the list of "Dogs that are Hard to Groom" because they're likewise hairy but more importantly, bigger that your average dogs. Dogs from the terrier family are also hairy so if you're not diligent enough, the grooming procedures might give you a headache.
Collies or shelties have been, in my opinion, awfully difficult to bathe and groom. Their long, thick fur needs constant attention to make sure no knots develop or nothing gets caught in the fur. (Wiping of the rear is always needed. Yucky stuff sticks, unfortunately.)