I loved the first year of Heroes, but felt that the rest was merely "watchable": every time they killed someone or changed their character it would inevitably turn out to revert back to the way it was a few episodes later.
There is talk of a "concluding" movie, but I thought that it was a good place to finish anyway.
Might I suggest you check out Fringe and Criminal Minds?
I was looking forward to the rumoured Global Frequency series, but things seem to have gone a bit quiet. If you can track down the pilot from the first time they tried to launch the show, it's well worth the effort.