If you're considering going into medicine, I'd absolutely say triple science instead of German.
Imho I'd try and take both; in order to get the English Baccalaureate (or something like that) you need to take a language and I believe (but not certain) a few uni's do require language GCSE even for courses unrelated to languages.
However if you're set on your other options, judging by what you want to do, definitely science