Who are DD's main antagonists? Kingpin, Bullseye... who else? They seem pretty FX-light characters.
The Hand for sure; otherwise... New York's organized crime?
Ones that stick in my mind, Mr. Fear and The Owl, especially from Gene Colan's run in the 70s. Mr. Fear might face accusations of ripping of Nolan's Batman, but is actually an excellent recurring villian in Daredevil since the 60s.
The Owl is both a powered villian one-on-one, and also a crime lord. I always found him especially creepy and dramatic, especially with Colan's brilliant artwork. If they can't use Kingpin, then the Owl is certainly an excellent choice. He has some kind of flight power, but this could also just be portrayed as "gliding" using his big coat.
Then there is Stiltman, who could be portrayed as an Iron Man wannabe. It's hard to take him seriously, but a good writer could do something with him.