i only watch heroes and prison break, and sometimes House, prison break was awesome in season 1, season 2 was ok and 3 was crap, the new season is good though, i watch it for T-bag's evilness and scofields brilliant plans, he is always one step ahead of everyone in the show.
heroes has been very good (except for last season), i don't like few things in the plot, hero nakamura and syler make heroes watchable