10 Great TV Shows That Went Downhill (And Then Redeemed Themselves)

3. 24 (2001 - 2010)

After five relentlessly entertaining seasons, the writers of 24 must have thought that they could do no wrong: for five years, 24 delivered great season after great season, throwing iconic counterterrorist agent Jack Bauer from one terrible day to another. It wasn't just the format that made 24 so great over the years: it was the way that it maintained suspense and kept Jack true to character despite the increasingly explosive plotlines.

But great things can't last forever, and thus 24 finally made its first bad season of television. "I feel as though the story made a very wrong turn in season 6," said showrunner Howard Gordon of the ill-judged collection of episodes comprising the season, which have since come to mark the point when 24 lost its way. Despite a strong start, there were far too many unbelievable plot twists and arbitrary links to previous events; it was a mess.

Thankfully, the people behind the scenes realised that they'd taken things way too far with season six, and set about creating a worthy season seven. Though the results weren't quite enough to match the brilliance of Emmy award-winning fifth season, season seven shook things up to such an extent that you had to be impressed: Jack was out of Los Angeles for the first time and in Washington D.C., standing trial for his questionable methods.

This switch-up helped 24 to regain its footing whilst also moving things in a new direction, and - in the wake of season six's failings - made for one of the most thrilling seasons to date (season eight followed suit, keeping things fresh with a story based in New York City).