De Palma is a great filmmaker, one that should be applauded for making films in a variety of different genres, even if some of his forays into new realms (MISSION TO MARS, in particular) are terrible. Across his filmography there are very few mediocre or bad films, the majority are well above average-excellent.
I count CARLITO'S WAY, DRESSED TO KILL and BLOW OUT among my personal favourites and I love CARRIE, SCARFACE, THE UNTOUCHABLES and CASUALTIES OF WAR.
I actually think he's very underrated and certainly someone who should be acknowledged as a master of cinema, rather that the Hitchcock tribute act many smug journalists would have you believe.