The Last Ship. I'm not sure if i should list this since the title of the thread is 'Good Shows that became disappoing' and while TLS wasn't good, i found it midly interestnig . Problem is the main premise got wrapped up towards the end of the first season, and the end of the first season changed the story complete. And then the ending of the first episode is entirly wrapped up with 2 episodes of the second season. The second season just seemed to be a mess, the idea that alot of America could be won over by a cult like that within such a short space of time seems insane to me. And the fact it has a 3rd season beggars belief.
I quite enjoyed The Last Ship. The fact that the country needs to be rebuilt from scratch means that there's a couple more seasons left in it yet, so long as viewer figures keep up.