Totally agree on the Casa Carmina recommendation. And if you stay there, I would highly recommend taking an afternoon bus to Cudillero to visit this off-Camino jewel of a little town. Touristy yes, but understandably so. I was there on a weekday afternoon in June, though, and it wasn´t at all packed with tourists. The bus stop is very close to the albergue.
Another of my favorite albergues on the "second half" of the Camino del Norte is
O Xistral, about 6 km after Abadín and before Vilalba. It's a terrific albergue with lots of comfortable outdoor spots for relaxing. Very rural, and the owners provide an evening meal. The albergue itself is really one of the nicest. Walking those extra 6 km beyond Abadín then make it easy for you to bypass Vilalba the next day (one of my least favorite places on the Norte, but others may disagree) and continue to Baamonde, if you are comfortable with days around 30. O Xistral to Baamonde is 32, I believe.
One last Norte recommendation -- try to get to Playa dos Catedrales, it is an amazing spot. Very crowded, but easy to get to from Ribadeo in a cab. Go at low tide. In high summer tickets are needed, but we went in June and it wasn´t an issue. The beach was crowded but not mobbed, as it must be in high summer.
And as a general recommendation, if you are a bit adventursome, check out some of the gorgeous coastal alternatives that are frequently within a km of the camino, which trudges along the side of the national highway.
This thread has been added to over the past few years by others, so it is a pretty good resource.