Very interesting and informative!Yes,Tabu is excellent-lovely lyricism.Did think of including it;perhaps i should have made my list longer!?Agree that Metropolis' message is shallow,but i love the visual impact.M makes far more interesting political and social points,certainly,and you're far from alone in thinking it Lang's best(it's also highly placed in this site's top 100,i see).No,i've not seen the updated Greed.I very much enjoyed Queen Kelly,but the version i saw was hardly the full film-horribly cut out in its prime.Where did the film go?,i wondered.Haven't seen Joyless Street,understand it's one of Pabst's best.Like many i enjoy Pandora's Box mainly for Brooks' wonderful,vivacious performance and her luminous beauty but it has its other strong points-the lighting is expert and the editing  and mise-en-scene rather more clever than i'd initially realised.Still,some elements do seem a little dated.The British Film Institute 360 classics list preferred Pabst's Secrets of the Soul to Joyless Street,if i remember rightly,but its selections were extremely idiosyncratic,and my reading's given the impression Joyless Street is better.Glad to be learning;i'm no great expert on silent films,just have a range of interests;something of a jack of all trades(and master of none)!I fling out my lists hoping for informed responses like yours.