Yes, some pubs do sell Guinness, but at least in my opinion it just doesn't taste like it does in London (not to mention Dublin)...
If you come to Germany, there's many kinds of good beer to be had. You know "Beck's", it is available in England, but there's so many others. Many breweries in the south do a "Hefeweizen" (can't translate this, sorry) which you should try!!
The best one round here is (of course) "Ulrichsbier" (no, it's not by me, but it's really good, I do not just mention it because my name is on it)!!!
