Union Berlin and Borussia Dortmund will be the most interesting matches while Bayern Munich and Freiburg are not very interesting because it will be easy to predict that Bayern Munich will lose again, while in Dortmund vs Union Berlin it will be more interesting because they have a very strong team and took first place at the top of the standings.
I don't think so, because seeing Freiburg's result in this week's match, it's clear they are struggling and their opponent is Bayern who incidentally are the defending champions and are now trying to improve the result with the new Galtier scheme.
This is clearly another exciting match because in the Bayern-Freiburg and Union-Dortmund matches if one wins then the position in the standings will definitely change.