It's not unusual for even the best TV shows to hang on past their freshness date--sorry, ''Simpsons.'' We pinpoint when it and some other faves could have quit, uh, heroically, from ''Heroes'' to (we'll say it) ''The Wire''
The Ideal End: ''Landslide,'' the penultimate episode of the first season, ends with the villainous Sylar looking out on New York, testing his newly-acquired radiation powers. With a smile of expectant triumph on his face, he says, ''Boom.'' It's a thrilling vision of evil triumphant, and a perfect encapsulation of everything Heroes did so well…for one season.
Badness Avoided: The disappointingly anticlimactic season finale, three seasons of steadily diminishing returns, an uncountable number of plotlines centering on power drains and/or amnesia, the infinite repetition of the phrase ''Claire Bear,'' the regression of Hiro into a man-child, and the never-ending ''Evil Circus'' season 4 story arc. Darren Franich