From Freiburg: East or west?

The possibilities are vast... if it were me I would catch a CityNightLine overnight train from Freiburg to Amsterdam or Berlin. You could go to Salzburg for a couple days, but you'd have to figure out other places you'd want to see nearby in Austria or Bavaria. I'd prefer big city experiences for a wintertime trip, but it all depends on you and your interests. Good luck / Gute Reise!

"I'd prefer big city experiences for a wintertime trip". Good instinct. I also would recommend a city-heavy itinerary in December. Much of the German countryside is beautiful, but with the short overcast days of winter, you can't see much. It all looks gray and hazy. Unless you want to go skiing, stick to cities.

Thank you for your responses! :D
Yeah, I think I'm definitely leaning towards bigger cities. I'm an Art History major, so cities that are art hubs/museum heavy are what I'm looking for. So if I go the Salzburg route, I'd continue on to Vienna. For an art history major (or any lover of the arts!) you can write and research all you like, but there's nothing like actually getting to see the work in person! And that's kind of what I'm going for.

Since you're an art lover and are ending up in Cologne, I think the Low Countries would be a great choice. Amsterdam has the Rijksmuseum and the Van Gogh Museum, Vermeer's Girl with a Pearl Earring is in the Hague (a nice town). Bruges and Ghent in Belgium are lovely cities- Bruges' Groeninge Museum has a lot of nice early Flemish paintings, and Ghent has Van Eyck's Adoration of the Mystic Lamb altarpiece (amazing). And any place in those countries is a relatively short train ride to Cologne (three hours or less). Of course you can't go wrong with Vienna. Going east you would be looking at some long days on the train and/or a flight. I believe Cologne/Bonn airport is a big budget airline hub- though demand for flights might be very high around New Year's.

Don't overlook the superb art collections in Dresden, Basel, Brussels, and (I haven't been there ...) Dusseldorf is very important in 20th Century art. Leipzig has one superb museum. and a lot of musical history. Note that quite a few of the paintings you'll see in Vienna were taken from these other countries by Empresses! Unfortunately, the Antwerp KMSKA museum is closed for construction, and only a little of its collection is on display in a variety of places. The Antwerp Meyer Van Den Berg museum is a little gem, but it's not worth a special trip unless you're a Brughel scholar. If you have a railpass, you might stop in Lille for the morning, on the way to Paris. They have lots of important works. It's not far from Bruges.

Art hub and museum heavyBerlin! It has the former East Berlin museum collections which competed with the West Berlin museum collections to see who had the best. You can save Paris for your next trip,though your friends are right; it does have the most museums and collections to see. One caveat, from what people have written on this board, you'll lose two museum days on Christmas and the 26th, whereas in France things will be closed only on the 25th.

Not sure about Berlin, but it is probably the same as here in Frankfurt, the museums share the holiday closings, so some are open on the 25th and may be closed on the 26th, and others have those days switched. But the 26th is less of a holiday in that sense and the majority of museums will be open. Some may even be open for a while on the 24th too. Check with each museum. I would also recommend being in Berlin over the holidays. You will find so much to do and they certainly have their share of galleries and museums.