I've never had my interest in something evaporate so quickly as 24 after it ended. Fox was smart when they began scheduling it in uninterrupted season blocks in the fourth year. Even when the show went of the rails, that provided enough inertia to keep me coming back.
Now, though? I can barely remember the cliffhanger the series ended on (and why did they end it on a cliffhanger again, when they knew it would be cancelled?). Meh.
It wasn't a cliffhanger. It ended with Jack going on the run. The writers said that 24 was always quite tragic and they wanted a suitably sad ending. At the start of Day 8, Jack had a nice life with his daughter and her family. During the course of that day, he had the hope of life with Renee. By the end of the day, Renee was dead and Jack was forced to go on the run, with little, if any, hope of seeing his family again. President Taylor, previously seen as a good woman, had been on the verge of sealing an historic peace deal with fake-Iran but by the end of the day had destroyed her Presidency with her ambition to secure that deal, as she took increasingly wrong 'realpolitik' steps to ensure that it went through.