Definitely my favorite TV show right now. The show ended it's 2nd season a couple of days back in the US with Sylar getting back his power after getting a virus causing him to temporarily be powerless. I watched season 2 online and am now in the process of finishing season 1.
In season 1... the gang was able to save New York from total destruction and was able to stop Sylar who ended up losing all his powers after contacting a rare virus that affects people with abilities like him... In season 2 the gang tries to stop a major event that would wipe out half the world's population.
In this season Sylar will regain his powers after getting the antidote from Mohinder Suresh... his blood combined with the Claire's blood.