Spoilers 
 4 just because I got some twisted enjoyment in seeing Light bite it. Gah, was he annoying at the end and needed someone to bitch slap that smug from his face. I abandoned reading this series years ago after L's death and it took this long for me to pick this up again and finally finish it. The series doesn't really get back to what it was when L was there, it becomes repetitive, monotonous and Mello and Near were nowhere near as interesting as L. Maybe if they'd worked together but meh, just meh. 
 ...I'm gonna go read some doujinshi.