In your lists you guys are forgetting the somewhat recent The Visit (2015). Not a great film, but at least a decent one, unlike The Last Airbender (2010). I guess it can be considered the starting point of Shyamalan's return to form.
Also missing from the lists, probably because it's better to forget it even exists: After Earth (2013). This Will & Jaden Smith SF adventure is supposedly extremely dumb, pretty terrible and, even worse, some sort of scientology inspired thing... That's one of the only three Shyamalan directed movies I have not seen, the other two being Praying with Anger and Wide Awake, the movies he made before The 6th Sense.
Also, while we complain about the quality of MNS' movies, the guy remained a pretty safe bet through his career. Let's look at budget and domestic box office for his movies:
The 6th Sense: $40m -> $293m
Unbreakable: $75m -> $95m
Signs: $72m -> $228m
The Village: $60m -> $114m
Lady in the Water: $70m -> $42m OUPS! Probably still in the red even with the foreign box office.
The Happening: $48m -> $64m
The Last Airbender: $150m -> $131m OUPS! Probably in the green thanks to foreign box office ($188m). Also, by far his highest budget film and he got to helm it after two film that did not inspire confidence!
Devil: $10m -> $33m Not directed by MNS, but produced by him and based on one of his stories.
After Earth: $130m -> $60m OUPS! Probably not saved by the $183m of foreign box office.
The Visit: $5m -> $65m That's some serious return on investment!
Split: $9m -> $138m Not only is that some tremendous return on investment, that's the third highest domestic grossing film of MNS' career!