i agree, Rammstein is not goth style, it's because of the guitar riffs that make them sound heavy. they are a cross between metal and electronica. if people listen to the music properly rammstein are just saying the lyrics then break out into a melodic chorus. the only time where they are yelling is never, they sing loudly. its kinda hard not to sing passionately and have the same outcome.
gothic on the other hand has orchestral instruments in it and is more eerie with lyrics that have hidden meanings or subliminal messages...