Headed to Brussels, Amsterdam, and Berlin on the 26th

I would take the train from Brussels to Brugge and spend my time there. But that's just a personal preference and not really an answer to your question. Brugge is absolutely amazing.

I go to Amsterdam fairly often. Tell me what sort of stuff you are looking for. I generally stay out of the City Centre/ DAM area as its usually over run with tourists but this time of year it won't be so bad. But prepare yourself for shitty, windy, cold, wet weather. A couple of brown bars that serve great beer in the center are Cafe Spuyt, Wildeman and Gollem. You can get great belgian beers such as Cantillion and Westvleteren 12 at those places. I aslo like Gollem's Overtoom (street) location which is about a 15 minute walk out of the city center. We usually stay in an airbnb in the Overtoom area as that is where a lot of locals hang out. Brewery Troost in Westergas Park is better than Brouwerij 't IJ. Brewery 't ij is over run with tourists but again, this time of year will be more locals and it is at the base of a big windmill....But their beer is mediocre. Proeflokaal Arendsnest is another great old bar that serves only dutch beers. I always hit it at least twice when I am in amsterdam. I usually suggest people rent a bike to get around but again....the weather will suck. If you are at all adventurous, the Vondel Bunker, which is an old Cold War bomb shelter underneath a road in Vondel Park has some counter-culture bands on some nights. Looks like Dec 28th has some bands playing. Its a weird scene full of misfits....nothing scary...more like misfit geeks.

I have a google map with restaurants and bars pinned that I can share if I can figure out how.

I second Brugge over Brussels.

Yeah I liked Brussels it had more to do, but Antwerp was more fun than Brugge as well... a lot of the southern area was really nice such as Leige and Dinant