Which beer, that is available in Germany, can you recommend that is more bitter than Jever?
Or, to re-phrase the question: What is the beer with the most hop that you know of, in Germany?
Well, when it comes to very hoppy beers nowadays, I can't help thinking about American IPAs. It's not even close to any german style, off course, but if you are looking for hops, that's the one style to go for.
Fortunately, there are some german microbreweries making IPAs there, like Hans Müller Sommelierbier's Backbone Splitter IPA, Ale-Mania's Imperial IPA and Crew IPA. I just don't know how available they are over there.
In general, german styles aren't so hop-forward, favoring balance over excess. Styles like Munich Helles and German Pilsners have a definite hop profile, which I find just the exact right amount to balance malt and compose the aroma profile, but nothing overwhelming like an IPA. The rare doppelstick style (double altbier) has a high IBU count, but just to balance the malt sweetness, which is massive in this style, and not to stand alone.
Californian brewery Stone is going to open a production plant in Berlin soon, so their beers will be available when it kicks off. And, just in case you aren't aware, Californian beers = loads of hops. So, keep an eye open.