Yes, Downfall (2004) was a great film however if you don't speak German it is totally confusing.
For instance seeing the subtitle 'The entire Luftwaffe should be strung up at once' just fails to have the same zing as
"Die gesamte Luftwaffe sollte auf einmal oben aufgereiht werden!!!!!!
Another great film so many miss is "Let the right one in" as the English subtitles are poor and take away the chemistry between the two leads that is so compelling.
Just because a film is subtitled it should not be considered 'boring'