The number one secret in making (and enjoying) a TV show is to know when to stop. I was advised to stop at the end of Heros Season 1, and maybe thanks to that I quite enjoyed it.
It's got some innovative twists (for me as a non-superheros fan, anyway) and the pace didn't drag, which is always a welcome thing for any TV show. The diverse mix of characters were also pretty good; almost all of them were interesting except one or two. It was tempting to continue watching, but I knew better.