Thou shalt NOT learn Swabian, the dialect spoken in Berlin, the capital of Germany.
EDIT: This is answer has two sides. The serious side is that the Standard German in Germany is not identical with any German regional dialect (even though there is a "long-standing de facto standard pronunciation" which "is similar to the formal German spoken in and around Hanover"). Not only that, but as you can see in the same Wikipedia article, there is actually not only one version of Standard German, but three: "German Standard German, Swiss Standard German and Austrian Standard German" (the first being the Standard German for [the Federal Republic of] Germany).
The not so serious side of the answer is that it's very tongue in cheek - I was trying to make my fellow Germans smile (I hope I didn't offend anyone). The pun being 1) that the traditional dialect of Berlin is not Swabian but Berlinerisch and 2) that there have been tensions between some of the local populace and the Swabians (Schwaben) who came to Berlin after the German unification (the term 'Schwaben' also "being used as a Synonym for all sorts of well-to-do west-German immigrants").