for me if the shows goes for more then 3 season it becomes boring. Afterward writers write what they think it will sell and what people might want to see. I used to love Ally watched every episode but when the third season started i was left wondering why did i watch this in the first place (oh yes music from Vonda Shephard). Ally is presented as a babe yet any other female charater on the show is much much sexier than her yet men keep falling for her.
Currentlly i am obssesed with Alias, Six Feet Under, Will and Grace, maybe Friends ( they lost their ways now for 3 season they do not know what should they do with them and the only reason this is still on because no one has made it to the big screen plus they get a million bucks for every episode)
Can't stand Roswell (Max Evens gotta to be the most boring tv character and Liz needs a bucket around her neck everytime she sees him she starts to drool), never watched West Wing, hate La Famme Nikita,