The show Lost

[Psychic Octopus]

Are you crazy? The fourth, fifth and sixth seasons just get more bizarre and string you along.

^^^

You can still enjoy it, just make sure to stop by Season 6 (though truthfully after Eko stopped being a major character it jumped the shark) and mentally substitute an ending. Whatever theory you come up with will undoubtedly be more logical and better written than what's 'canon.'

[Psychic Octopus]

No, really, the show ended terribly. Terribly. I started watching on the premiere date, and was captivated. The writers were stringing us along. I admit to a few "wow" moments during Season 5, especially the ending bits, but I absolutely loathed Season 6. They didn't tie up a lot of the loose ends. And the whole bit about Widmore ended... awkwardly.

Anyways, the ride from Season 1 to Season 4 is pretty awesome. From there onward it becomes pretty disappointing. The whole "Flash-sideways" parts were annoying and tedious.

Yeah, Eko was pretty epic. I remember being so sad that he died. I liked Desmond, Eko, and Locke. There were a few other cool characters.