If I compare between Bayern Munich and Dortmund, I think I'm more interested in Dortmund. Because after all, Bayern Munich only has a record as a club that really dominates the Bundesliga by winning consecutive titles. But in fact, Bayern Munich also quite often get great players from Dortmund. Also about Dortmund, even though Dortmund often sell key players and star players, but Dortmund has always managed to build a team well. The proof is, Dortmund has always managed to challenge Bayern Munich in the title race and because of that, I think Dortmund is a very unique team. Because no team can produce great players every season like Dortmund and also be willing to sell them, it's like a tradition that only Dortmund seems to have.
You can't compare Dortmund to Bayern Munich because Munich are the best club in the Bundesliga, they are in the top every season in the league and even perform well in the Champions League but last season their performance was very weak, and they too are in the best club in the world, last seasons Dortmund try there best to win the league but they can't, and now they need some players because they sold their best midfielder in Dortmund to Bayern Munich.
If Dortmund makes good players every season it doesn't make them to be better than Bayern Munich. The best team is always supposed to be win trophies, so I think Dortmund they are trying as a team to always be in top position and participating in Champions League but I won't rate them to be the best team in Bundesliga league, but I can say they are one of the best after Bayern Munich. Dortmund have chances to win trophies to become the best if they really want to.
Bayern Munich remains the best team in Bundesliga, despite their challenge they went through in the season, they where still able to get the championship league of the league, this is how to know if a team is the best team in the league. I believe in the next season Bayern Munich will still prove to fans they are the best because they always choose winning trophies as their target , they buy the best players to make sure they win trophies.