I'm into Star Wars and Super Hero Lego pretty heavily. They're my current collecting addiction. I try to focus on the Batman stuff as far as DC goes. Have both Batcaves and both Arkham Asylums. Other than the SDCC stuff Im pretty sure I have every version of Batman Lego has made. Also have a pretty large Justice League roster thanks to all the Lego customizers out there.
Marvel wise its all about the minifigs. I think the only Marvel ones Im missing are the Guardians of the Galaxy. My weakness is Iron Man armors, Ive got 28 different armors at this point. I may have a sickness!
As for Star Wars, Im Empire-centric. Ive got decent sized armies of Stromtroopers,Sandtroopers,Snowtroopers and Biker Scouts. I collect the Empires vehicles too, 'cept the Star Destroyer. I have the minifigs from the set but not the set itself. Its a bit large to try to display/store. Thanks to "Force Friday" a few weeks back I picked up and laid away some of the Force Awakens stuff too.

Lego is pricey addiction to have. Thankfully I have some self discipline or Id be picking up Scooby Doo,TMNT,and the Ghostbusters stuff. They're pretty cool, but Ive gotta draw the line somewhere!