I too would have to say that overall NCL is my favorite cruise line. It's not the only cruise line I sail but it is my favorite.
Reasons: Freestyle cruising.
Overall cruise fares.
The main reason, we had a few problems on past cruises and NCL was there to make things right.
Ncl ships: Sky (2002), Pride of Aloha (July 4,2004),
Star (2005 & 2009), Pearl (2008 & 2010)
and Jewel (2013).