I haven't been to Germany, but Poker in Europe has some information, perhaps dated, since the rake caps are in DM.
Looks like mostly 7cs, limit, spread limit and pot limit, also some PLHE and PLO.
From what the other poster said, it seems like there are some NLHE tournaments and 2 or 3 table tournaments, since all the TV exposure of that.
Seems like mostly just mid limit and somewhat higher rake than in North America and British Isles.
I would certainly give whatever games they have a try. Don't be an ugly American and look for everything just like at home.
Poker in Europe directory of German card rooms
Daily cash games.
Stud, Holdem, and Omaha.
Limit, Spread Limit and Pot Limit.
5% rake capped at DM 10
10-50 Spread Limit 7 Card Stud
7 Card Stud
10-50 Spread Limit
Pot Limit
Pot Limit 7 Card Stud
Daily cash games
Holdem, DM 20-100, pot limit
3 - 5% rake
7 Card Stud
10-20 Limit
10-50 Spread Limit
Pot Limit
Pot Limt Holdem, Stud and Omaha.
5 % rake, capped at DM 15