For those that watched the original anime and the OVAs now's the perfect time to start watching Hunter, as it's the begining of the new arc:
Gon and Killua are hired to investigate a strange insect leg that washed up on a beach. Genetic testing determines that the leg belongs to an abnormally large queen Chimera Ant which just happens to wash up on the shore of an island called the NGL (Neo Green Life). The Chimera Ants proceed to wipe most of the population out and spawn hundreds of offspring for next generation before Gon, Killua, and Kite arrive to stop her.
As somebody that has read the manga this arc is very good, the plot's very well done and offers some interesting views on humanity, good part of it is even set on a country that greatly reminds of Nort Korea, in fact it was inspired by it. Character development is also top notch, so i recoment every anime fan to watch it.